include <iostream>

using namespace std;

define ll long long

int main() { ll n,say; cin>>n; while(n!=0) { if(n%10%2!=0) { say++; } n/=10; } cout<<say; }

include<bits/stdc++.h>

using namespace std; int main() { long long r=0,i,n,son=0,cavab=0; cin>>n; while(n>0){ son=n%10;

    if(son%2!=0){
cavab=cavab+1; }


    n=n/10;}
cout<<cavab;

}

include <bits/stdc++.h>

using namespace std; int main() { long long n,say; cin>>n; while(n!=0) { if(n%10%2!=0) { say++; } n/=10; } cout<<say; }//NAHID ZEYD VE RESADDAN PROOOO!!!!!!!!!!!!!!!!!!!!!!!

include <iostream>

using namespace std; int main() { long long n,x[999999],i=0,max=-9999999,s,say=0; cin>>n; while(n!=0){ s=n%10; n/=10; x[i]=s; i++; } for(int j=0;j<i;j++){ if(x[j]%2!=0){ say++; } } cout<<say;

return 0;

}