#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int N=1e5+5;

int n,a[N];
ll L,R;

int main(){
	scanf("%d",&n);
	for(int i=1;i<=n;i++) scanf("%d",a+i);
	
	L=R=2;
	for(int i=n;i;i--){
		L=(L-1)/a[i]+1,R=R/a[i];
		if(L>R){ puts("-1"); return 0;}
		L*=(ll)a[i],R=(R+1)*(ll)a[i]-1;
	}

	printf("%lld %lld\n",L,R);
	return 0;
}