cifre003

#include <iostream>

using namespace std;
int n,nr,cn,s,uc,restulLuiSla3;
int main()
{
    cin>>n;
    cn=n;
    while(cn)
    {
        s=s+cn%10;
        cn=cn/10;
    }
    restulLuiSla3=s%3;
    //practic daca suma cifrelor nr meu are restul R cand o impart la 3,
    // atunci pot elimina orice cifra care are restul R la impartirea prin 3
    while(n){
    uc=n%10;
    if(uc%3==restulLuiSla3)
        nr++;
    n=n/10;
    }
    cout<<nr;
    return 0;
}