#include <bits/stdc++.h>
using namespace std;
struct aa{
	int a,b;
}ma[10000];
int main(){
	freopen("fenshu.in","r",stdin);
	freopen("fenshu.out","w",stdout);
	int n,m,b[10000];
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>ma[i].b>>ma[i].a;
	}
	for(int i=n+1;i<=n+m;i++){
		cin>>b[i];
	}
	int j,sum=0,dum=0;
	for(int i=1;i<=n+m;i++){
		j=ma[i].a;
		if(i>=2&&i<=n){
			ma[i].a=ma[i].a*ma[i-1].a;ma[i].b=ma[i].b*ma[i-1].a;ma[i-1].b=ma[i-1].b*j;
			dum=ma[i].a;sum=ma[i].b+ma[i-1].b;ma[i].b+=ma[i-1].b;
		}
		if(i>n&&i<=n+m){
			if(sum%b[i]==0){
				sum/=b[i];
			}else{
				dum*=b[i];
			}
		}
	}
	for(int j=2;j<=min(sum,dum);j++){
		for(int i=2;i<=j;i++){
			if(sum%i==0&&dum%i==0){
			sum/=i;dum/=i;
			break;
		}
		}
	}
	if(sum%dum==0){
		cout<<sum/dum;
		return 0;
	}
	cout<<sum<<" "<<dum;
	return 0;
}