View Compilation Error

0_0_25155969_16134.cpp: In function 'int main()':
0_0_25155969_16134.cpp:16:20: error: 'A' was not declared in this scope
             f3 = ((A * f2) + (B * f1)) % mod;
                    ^
0_0_25155969_16134.cpp:16:31: error: 'B' was not declared in this scope
             f3 = ((A * f2) + (B * f1)) % mod;
                               ^