View Compilation Error

0_0_34590940_18424.cpp: In function 'll fpow(ll, int)':
0_0_34590940_18424.cpp:25:7: error: unable to find numeric literal operator 'operator""a'
   a = 1a * a % mod;
       ^
0_0_34590940_18424.cpp:25:7: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes