arr = list(map(int,input().split()))#1 2 3 4
prefix = []
c = 0
for x in arr:
    c+=x
    prefix.append(c)#1 3 6 10
print(prefix)
def range_x (L,R):
    if L ==  0:
        return prefix[R]
    else:
        return prefix[R]-prefix[L-1]
print(range_x(1,3))