#include <stdio.h>
#include <stdlib.h>

int main()
{
	char str[10000] = "";
	int ans = 0;
	scanf("%s", str, sizeof(str));

	for (int i = 0;str[i] != '\0';i++)
	{
		char* end;
		int num = strtol(&str[i], &end, 10);
		
		ans += num;
	}

	printf("%d", ans);

	return 0;
}