# coding: utf-8

#l, k = map(int,input().split())
#l = int(input())
#N = int(input())
#B = list(map(int,input().split()))
l = [str(i) for i in range(1,10)]
S = list(input())
ans = 0
for a in S:
    if a in l:
        ans += int(a)

print(ans)