/in/foo.cc: In function 'int main()':
/in/foo.cc:20:17: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long int*' [-Wformat=]
 scanf("%I64d",&n);
                 ^
/in/foo.cc:21:24: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long long int' [-Wformat=]
 printf("%I64d\n",dfs(n));
                        ^