Rock2

#include <stdio.h>
#include <math.h>

int main()
{
    int input,Countzero=1,mod=10,ans;
    scanf("%d",&input);
    while(1)
    {
        ans=input%mod;
        if(ans!=0) break;
        mod*=10;
        Countzero*=10;
    }
    printf("%d",(Countzero-1)/9);
    return 0;
}