View Compilation Error

0_0_37534463_32362.cpp: In function 'long long int qpow(long long int, long long int)':
0_0_37534463_32362.cpp:11:13: error: 'ans' was not declared in this scope
   if(k & 1) ans = ans * n % mod;
             ^
0_0_37534463_32362.cpp:13:3: error: 'a' was not declared in this scope
   a = a * a % mod;
   ^