asdfas

#include <stdio.h>
#include <climits>
#include <limits>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <iostream>
#include <fstream>
#include <algorithm>
#include <map>
#include <vector>
#include <set>
#include <queue>

long double meals[105];
long double a, b;
long long int cases, size;

using namespace std;
int gcd(long long int x, long long int y) { return y ? gcd(y, x % y) : abs(x); }

int main()
{
    while(true) {
        cin >> size;
        if(size == 0) break;
        cin >> a;
        cin >> b;

        memset(meals, 0x00, sizeof(long double)*105);
        for(long long int i = 0; i < size; i++) {
            long long int meal;
            cin >> meal;
            meals[meal]++;
        }

        long double minsum = -1;
        long long int minden, minnum;
        long long int minsden, minsnum;
        long long int cden, cnum;
        for(long long int inum = 1; inum <= 100; inum++) {
            for(long long int iden = 1; iden <= inum; iden++) {
                long double plate = ((long double)inum) / ((long double)iden);
                long double sum = 0;
                long long int snum = 1;
                long long int sden = 1;
                for(long long int meal = 1; meal <= 100; meal++) {
                    if(meals[meal] == 0) continue;
                    if(ceil(meal/plate) > 3) {
                        sum = minsum;
                        break;
                    }
                    long double cost = b*ceil(meal/plate) + max((long double) 0.0,a*(ceil(meal/plate)*plate - meal));
                    long long int cnum = b*ceil(meal/plate)*iden;
                    long long int waste = a*(ceil(meal/plate)*inum - meal*iden);
                    if(waste > 0) cnum += waste;
                    long long int cden = iden;

                    snum = (sden*cnum + cden*snum)*meals[meal];
                    sden = sden*cden;
                    sum += cost*meals[meal];
                }
                if(sum < minsum || minsum < 0) {
                    minsum = sum;
                    minnum = inum;
                    minden = iden;
                    minsnum = snum;
                    minsden = sden;
                }
            }
        }
        minsnum -= minsden;
        int g = gcd(minsnum, minsden);
        minsnum = minsnum / g;
        minsden = minsden / g;

        if(minsden == 1) {
            printf("%lld\n", minsnum);
        } else {
            printf("%lld / %lld\n", minsnum, minsden);
        }
    }


  return 0;
}