View Compilation Error

1_734_804_25391.cpp: In function 'int main()':
1_734_804_25391.cpp:74:34: error: unable to find numeric literal operator 'operator""ans'
   printf("Case #%d: %I64d\n",c+1,9ans);
                                  ^
1_734_804_25391.cpp:74:34: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes