def binary_sum(S, start, stop): 
    if start>=stop: 
        return 0 
    elif start == stop-1: 
        return S[start] 
    else: 
        mid= (start+stop)//2 
        return binary_sum(S, start, mid)+binary_sum(S, mid,stop) 
print("\t summing the elements of a sequence using binary recursion") 
print("\t -----------------------------------------") 
S=[] 
print("Input") 
print("- - - - -") 
n=int(input("enter the no of elements:")) 
print("Enter the elements one by one:") 
for i in range(n): 
    m=int(input()) 
    S.append(m) 
print("The given sequence of elements=",S) 
r=binary_sum(S, 0, n) 
print("output") 
print("- - - - - -") 
print("The given sum of sequence of elements=",r)