How to calculate this sequence?

Question

Python

Given natural numbers m,n, real numbers A[1],A[2],...,A[m*n]. Calculate A[1]*A[2]*...*A[m]+A[m+1]*A[m+2]*...*A[2*m]+ ...+ + A[(n-1)*m+1]*A[(n-1)m+2]*...*A[n*m].

This is what the task looks like on paper :

A python solution is preferred, but not required. Any help would be useful to me, since my problem is rather that I don’t understand how to do it purely mathematically.

Answer 1

Mmm... what's so difficult about it?

s = 0
for i in range(0, n):
  p = 1
  for j in range(1, m+1):
    p *= a[i* m+j]
  s += p