View Compilation Error

0_0_26573601_26672.cpp: In function 'll quick_pow(ll, ll)':
0_0_26573601_26672.cpp:36:18: error: 'mod' was not declared in this scope
             ans%=mod;
                  ^
0_0_26573601_26672.cpp:39:12: error: 'mod' was not declared in this scope
         a%=mod;
            ^
0_0_26573601_26672.cpp: In function 'll C(int, int)':
0_0_26573601_26672.cpp:49:10: error: 'mod' was not declared in this scope
     ans%=mod;
          ^
0_0_26573601_26672.cpp: In function 'll solve(int)':
0_0_26573601_26672.cpp:64:19: error: 'mod' was not declared in this scope
             temp%=mod;
                   ^
0_0_26573601_26672.cpp:67:14: error: 'mod' was not declared in this scope
         ans%=mod;
              ^
0_0_26573601_26672.cpp: In function 'int main()':
0_0_26573601_26672.cpp:76:17: error: 'mod' was not declared in this scope
         sum[i]%=mod;
                 ^