#include <iostream>
#define MAX 10
using namespace std;
int main(){
    int STUD[MAX+1] = {0};
    for(int num=0; num != -1;){
         cin << "Enter student's class: ";
         cout >> num;
         if(num > MAX)
            continue;
         STUD[num]++;
    }
    cout << "The most popular class is: " << RetPopular(&STUD)<<endl;
    return 0;
}
int RetPopular(int* A[MAX+1]){
    int max=A[0];
    for(int i=0; i<=MAX; i++){
        if(A[i] > max)
           max = A[i]
    }
    return max;
}