View Compilation Error

0_0_14720561_30356.cpp: In function 'void dfs(int)':
0_0_14720561_30356.cpp:494:15: error: 'm' was not declared in this scope
     FOR(i, s, m){
               ^
0_0_14720561_30356.cpp:20:46: note: in definition of macro 'FOR'
 #define FOR(i, a, b) for (int i=int(a);i<int(b);++i)
                                              ^
0_0_14720561_30356.cpp:505:14: error: 'm' was not declared in this scope
     if (s == m){
              ^