diff --git a/conf.json b/conf.json
index e41ec47..1ec2a26 100644
--- a/conf.json
+++ b/conf.json
@@ -1,121 +1,121 @@
 {
-  "stages": [
-    {
-      "name": "compile",
-      "executor": {
-        "name": "sandbox",
-        "with": {
-          "default": {
-            "args": [
-              "g++",
-              "b.cc",
-              "-o",
-              "a"
-            ],
-            "env": [
-              "PATH=/usr/bin:/bin"
-            ],
-            "cpuLimit": 10000000000,
-            "memoryLimit": 104857600,
-            "procLimit": 50,
-            "copyInDir": ".",
-            "copyOut": [
-              "stdout",
-              "stderr"
-            ],
-            "copyOutCached": [
-              "a"
-            ],
-            "stdin": {
-              "content": ""
-            },
-            "stdout": {
-              "name": "stdout",
-              "max": 4096
-            },
-            "stderr": {
-              "name": "stderr",
-              "max": 4096
-            }
-          }
-        }
-      },
-      "parser": {
-        "name": "result-status"
-      }
-    },
-    {
-      "name": "run",
-      "executor": {
-        "name": "sandbox",
-        "with": {
-          "default": {
-            "args": [
-              "./a"
-            ],
-            "env": [
-              "PATH=/usr/bin:/bin"
-            ],
-            "cpuLimit": 1000000000,
-            "memoryLimit": 104857600,
-            "procLimit": 50,
-            "copyOut": [
-              "stdout",
-              "stderr"
-            ],
-            "stdout": {
-              "name": "stdout",
-              "max": 4096
-            },
-            "stderr": {
-              "name": "stderr",
-              "max": 4096
-            },
-            "copyInCached": {
-              "a": "a"
-            }
-          },
-          "cases": [
-            {
-              "stdin": {
-                "src": "./cases/1.in"
-              }
-            },
-            {
-              "stdin": {
-                "src": "./cases/2.in"
-              }
-            }
-          ]
-        }
-      },
-      "parser": {
-        "name": "diff",
-        "with": {
-          "cases": [
-            {
-              "outputs": [
-                {
-                  "score": 100,
-                  "fileName": "stdout",
-                  "answerPath": "./cases/1.out",
-                  "ignoreWhitespace": true
+    "stages": [
+        {
+            "name": "compile",
+            "executor": {
+                "name": "sandbox",
+                "with": {
+                    "default": {
+                        "args": [
+                            "clang++",
+                            "b.cc",
+                            "-o",
+                            "a"
+                        ],
+                        "env": [
+                            "PATH=/usr/bin:/bin"
+                        ],
+                        "cpuLimit": 10000000000,
+                        "memoryLimit": 209715200,
+                        "procLimit": 50,
+                        "copyInDir": ".",
+                        "copyOut": [
+                            "stdout",
+                            "stderr"
+                        ],
+                        "copyOutCached": [
+                            "a"
+                        ],
+                        "stdin": {
+                            "content": ""
+                        },
+                        "stdout": {
+                            "name": "stdout",
+                            "max": 4096
+                        },
+                        "stderr": {
+                            "name": "stderr",
+                            "max": 4096
+                        }
+                    }
                 }
-              ]
             },
-            {
-              "outputs": [
-                {
-                  "score": 100,
-                  "fileName": "stdout",
-                  "answerPath": "./cases/2.out",
-                  "ignoreWhitespace": true
-                }
-              ]
+            "parser": {
+                "name": "result-status"
+            }
+        },
+        {
+            "name": "run",
+            "executor": {
+                "name": "sandbox",
+                "with": {
+                    "default": {
+                        "args": [
+                            "./a"
+                        ],
+                        "env": [
+                            "PATH=/usr/bin:/bin"
+                        ],
+                        "cpuLimit": 1000000000,
+                        "memoryLimit": 104857600,
+                        "procLimit": 50,
+                        "copyOut": [
+                            "stdout",
+                            "stderr"
+                        ],
+                        "stdout": {
+                            "name": "stdout",
+                            "max": 4096
+                        },
+                        "stderr": {
+                            "name": "stderr",
+                            "max": 4096
+                        },
+                        "copyInCached": {
+                            "a": "a"
+                        }
+                    },
+                    "cases": [
+                        {
+                            "stdin": {
+                                "src": "./cases/1.in"
+                            }
+                        },
+                        {
+                            "stdin": {
+                                "src": "./cases/2.in"
+                            }
+                        }
+                    ]
+                }
+            },
+            "parser": {
+                "name": "diff",
+                "with": {
+                    "cases": [
+                        {
+                            "outputs": [
+                                {
+                                    "score": 100,
+                                    "fileName": "stdout",
+                                    "answerPath": "./cases/1.out",
+                                    "ignoreWhitespace": true
+                                }
+                            ]
+                        },
+                        {
+                            "outputs": [
+                                {
+                                    "score": 100,
+                                    "fileName": "stdout",
+                                    "answerPath": "./cases/2.out",
+                                    "ignoreWhitespace": true
+                                }
+                            ]
+                        }
+                    ]
+                }
             }
-          ]
         }
-      }
-    }
-  ]
+    ]
 }