/in/foo.cc: In function 'int main()':
/in/foo.cc:11:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   for(int b=1;b<=(n-a)*2+1;++b) 
   ^~~
/in/foo.cc:13:4: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
    cout << endl;
    ^~~~