/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:8:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(cur>n)  ans++;
     ~~~^~
/in/foo.cc:9:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=1;i<=n;i++)
              ~^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:25:15: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long unsigned int*' [-Wformat=]
  scanf("%d",&n);
             ~~^