a list is given arr = [2, 1, 10, 5] Write a function with a for list that sums all the numbers in the list with each other ((2+1)+(2+10)+(2+5)+(1+10)+(1+5)+(10+5) ) The result should be this: res = 54

def sum_list(lst):
    sum = 0 
    for i in range(len(lst)):
        for j in range(len(lst)):
            if i != j:
                sum += lst[i] + lst[j]
    return sum
    
sum_list([2, 1, 10, 5])