View Compilation Error

0_0_25630458_32540.cpp: In function 'long long int Cnm(int, int)':
0_0_25630458_32540.cpp:20:26: error: 'mod' was not declared in this scope
     return fac[n]*inv[m]%mod*inv[n-m]%mod;
                          ^
0_0_25630458_32540.cpp: In function 'int main()':
0_0_25630458_32540.cpp:40:52: error: 'mod' was not declared in this scope
         while(ni[j]<N){res=(res+Cnm(N-1,M))*inv[2]%mod;N--;}
                                                    ^
0_0_25630458_32540.cpp:41:44: error: 'mod' was not declared in this scope
         while(ni[j]>N){res=(2*res-Cnm(N,M)+mod)%mod;N++;}
                                            ^
0_0_25630458_32540.cpp:42:42: error: 'mod' was not declared in this scope
         while(mi[j]<M){res=(res-Cnm(N,M)+mod)%mod;M--;}
                                          ^
0_0_25630458_32540.cpp:43:45: error: 'mod' was not declared in this scope
         while(mi[j]>M){res=(res+Cnm(N,M+1))%mod;M++;}
                                             ^