#include <stdio.h>
int main()
{
    int m,n;
    int a,b,c,cnt;
    while(scanf("%d %d", &m, &n)!=EOF)
    {
        if(m==0&&n==0){return 0;}
        cnt=0;
        a=m/100+n/100;
        b=m%100/10+n%100/10;
        c=m%10+n%10;
        if(a>9)cnt++;
        if(b>9)cnt++;
        if(c>9)cnt++;
        if(b==9&&c>9){cnt++;b=b+1;}
        if(a==9&&b>9)cnt++;
        printf("%d\n",cnt);
    }
    return 0;
}