View Compilation Error

0_0_17881579_5348.cpp: In function 'int main()':
0_0_17881579_5348.cpp:173:13: error: 'q1' was not declared in this scope
             q1 += -i * q2 % modp + modp;
             ^
0_0_17881579_5348.cpp:173:24: error: 'q2' was not declared in this scope
             q1 += -i * q2 % modp + modp;
                        ^
0_0_17881579_5348.cpp:178:13: error: 'q3' was not declared in this scope
             q3 += -(i + 1) * q4 % modp + modp;
             ^
0_0_17881579_5348.cpp:178:30: error: 'q4' was not declared in this scope
             q3 += -(i + 1) * q4 % modp + modp;
                              ^