# boj, 11720 : 숫자의 합, python3
N = int(input())
if N > 100 or N < 1:
print("N range error")
else:
num = list(input())
result = []
for i in num:
result.append(int(i))
if len(result) != N:
print("error")
else:
print(sum(result))
https://www.acmicpc.net/problem/11720