codeforce - Sum of Digits

#include<bits/stdc++.h>
using namespace std;
#define fastread()(ios_base::sync_with_stdio(false).cin.tie(NULL));
#define pb push_back
int cr=0;
int counter(string s)
{
    int sum=0;
    for(int i=0;i<s.size();i++)
    {
        sum+=s[i]-'0';
    }
    if(s.size()==1 && cr==0)cr=0;
    else cr++;
    if(sum>9)
    {
        s.clear();
        while(sum>0)
        {
            int x = sum%10;
            char c= x+'0';
            s.pb(c);
            sum/=10;
        }

        return counter(s);
    }
    //cr++;
    //if(sum==0 && cr==1)cr=0;
    return 1;
}
int main()
{
    string s;
    cin>>s;
    int x= counter(s);
    cout<<cr<<endl;
}