#include <stdio.h>
int main(){
int i[2];
char bun[10000];
scanf("%s",&bun);
i[0]=0;i[1]=0;
while(bun[i[0]]!='\0'){
if(abs(bun[i[0]]-53)<=4){i[1]+=(bun[i[0]]-48);}
i[0]++;
}
printf("%d\n",i[1]);
	return 0;
}