View Compilation Error

0_0_22617900_30080.cpp:6:15: error: expected initializer before numeric constant
 const int INF 0x3f3f3f3f
               ^
0_0_22617900_30080.cpp: In function 'int dfs(int, int, int)':
0_0_22617900_30080.cpp:25:3: error: 'vis' was not declared in this scope
   vis[v]=1;
   ^
0_0_22617900_30080.cpp: In function 'int max_flow(int, int)':
0_0_22617900_30080.cpp:48:11: error: 'vis' was not declared in this scope
    memset(vis,0,sizeof(vis));
           ^
0_0_22617900_30080.cpp:49:18: error: 'INF' was not declared in this scope
    int f=dfs(s,t,INF);
                  ^