View Compilation Error

0_0_17717470_32430.cpp: In function 'long long int quickPow(long long int, long long int)':
0_0_17717470_32430.cpp:48:35: error: 'mod' was not declared in this scope
         if(y & 1) res = res * x % mod;
                                   ^
0_0_17717470_32430.cpp:49:30: error: 'mod' was not declared in this scope
         y >>= 1; x = x * x % mod;
                              ^