View Compilation Error

0_0_20451418_24728.cpp: In function 'int main()':
0_0_20451418_24728.cpp:16:13: error: 'i' was not declared in this scope
         rep(i,1,n) graph[i].clear();
             ^
0_0_20451418_24728.cpp:16:18: error: 'rep' was not declared in this scope
         rep(i,1,n) graph[i].clear();
                  ^
0_0_20451418_24728.cpp:38:9: error: 'll' was not declared in this scope
         ll ans=0;
         ^
0_0_20451418_24728.cpp:41:26: error: 'ans' was not declared in this scope
         printf("%I64d\n",ans/2);
                          ^