/in/foo.cc: In function 'long long int calc(long long int, long long int)':
/in/foo.cc:16:9: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return ans;
         ^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:61:9: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
    else if (num==ans && ansx>tx) ansx=nx=tx,ansy=ny=ty;
         ^~
/in/foo.cc:45:5: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
  ans=calc(nx,ny);
  ~~~^~~~~~~~~~~~