#include<stdio.h>


int main(void)
{

int i=0,j=0,cnt=0;
char s[10000],c;

for(;;){
	if((c = getchar()) != '\n'){
		s[i] = c;
		i++;
		j++;
	}else	break;
		
}


for(i=0;i<j;i++){
	if(s[i]>='0' && s[i]<='9')
		cnt=cnt+(s[i]-'0');
}

printf("%d\n",cnt);

return 0;
}