题解

#include<bits/stdc++.h>
using namespace std;
typedef long long apple;
typedef bool pear;
pear apples(apple n){
    if(n>9&&n<100) return 1;
    else return 0;
}
int main(){
    apple n;
    cin>>n;
    if(apples(n)==1) cout<<"yes";
    else cout<<"no";
    return 0;
}