#include<stdio.h>
#define length 10000

int sumall(char s[],int size);

int main()
{
	char s[length]={0};
	int ans;

	scanf("%s",s);
	

	ans=sumall(s,length);
	printf("%d\n",ans);

	return 0;
}


int sumall(char s[],int size)
{
	int i,ans=0;
	for(i=0;s[i]!='\0';i++){
		if('0'<=s[i] && s[i]<='9'){
			ans=ans+(int)s[i]-'0';
		}

	}	
	return ans;
}