#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

//namaega184

int main(){
	int n;long long z[101];scanf("%d",&n);for(int i=0;i<n;i++)scanf("%lld",&z[i]);
	long long ans;
	
	printf("%lld/%lld\n",z[n-1],z[0]);
	return 0;
}