View Compilation Error

0_0_25946589_19022.cpp: In function 'int main()':
0_0_25946589_19022.cpp:52:83: error: 'solve' was not declared in this scope
             sum += (ll)pow(-1, i) * C(k + m - 1 - n * i, m - 1) % mod * solve(m, i) % mod;
                                                                                   ^