View Compilation Error

0_0_30755686_17958.cpp: In function 'int main()':
0_0_30755686_17958.cpp:36:26: error: unable to find numeric literal operator 'operator""ll'
         long long ans = -1e18ll;
                          ^
0_0_30755686_17958.cpp:36:26: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes