/in/foo.cc: In function 'int main()':
/in/foo.cc:17:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
     for(i=1;i<=n;i++)
     ^~~
/in/foo.cc:20:2: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
  for(i=1;i<=n;i++)
  ^~~
/in/foo.cc:9:23: warning: unused variable 'w' [-Wunused-variable]
     int n,m,i,j,ans=0,w;
                       ^