#include <stdio.h>
int main(void){
char s[11000];
int count;
int sum=0;
scanf("%s",s);
for(count=0;s[count]!='\0';count++){
if(s[count]>='0'&&s[count]<='9'){sum=sum+(s[count]-'0');}
}
printf("%d\n",sum);
}