#include<stdio.h>

int main(){
	char s[10001],c;
	int n=0,i;
	scanf("%s",s);
	for (i=0;s[i]!='\0';i++)if ('0'<s[i]&&s[i]<='9')n+=s[i]-'0';
	printf("%d",n);
	return 0;
}