#include<iostream>
#include<vector>
#include<string>
#include<cstdio>
using namespace std;
int ans;
int n;
int s;

void count_ans(int k,int C,int j){
    if(k==n){
        if(C==s){
            ans++;
        }
    }else{
        for(int i=j+1;i<10;i++){
            count_ans(k+1,C+i,i);
        }
    }

}


int main(){
    while(cin>>n>>s,(n!=0)||(s!=0)){
        ans=0;
        count_ans(0,0,-1);
        cout<<ans<<endl;
    }
}
