Model BAC 2016 Sub III Ex 3

///Model BAC 2016 Sub III Ex 3
#include <iostream>

using namespace std;


int main()
{ int n,c,r=0,k=0;
cin>>n;
  if(n==0){
    k=1;
    cout<<k;
  }
  else{
    while(n!=0){
    c=n%10;
    n=n/10;
    if(c==r){
        k++;///potrivire cifra rang
    }
    r++;

    }
    cout<<k;

  }

    return 0;
}