View Compilation Error

0_0_37310362_17324.cpp: In function 'void AmoureuxXJ()':
0_0_37310362_17324.cpp:128:54: error: 'A' was not declared in this scope
                     ans[i] += ((C[ num[j] ][k] *C[ n-A[j] ][i-k] )%mod * (1<<j))%mod;
                                                      ^