View Compilation Error

0_0_36703041_3737.cpp: In function 'void Solve()':
0_0_36703041_3737.cpp:66:8: error: unable to find numeric literal operator 'operator""llcnt'
 ans += 1llcnt(cnt-1)/2;
        ^
0_0_36703041_3737.cpp:66:8: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes