#include<bits/stdc++.h>
#include<algorithm>
using namespace std;
#define LL __int128
LL a, b;
LL read() {
    LL x = 0;
    string c;
    cin >> c;
    for(int i = 0; i < c.length(); i ++) {
        x *= 10;
        x += c[i] - '0';
    }
    return x;
}
LL gcd(LL x, LL y) {
    while(x > 0 && y > 0)
    {
    	LL t = x % y;
    	x = y;
    	y = t;
    }
    return x;
}
LL lcm(LL x, LL y) {
	return x / gcd(x, y) * y;
} 
int print(LL x) {
    if(x > 9) {
        print(x / 10);
        int y = x % 10;
        cout << y;
    }
    else {
        int y = x % 10;
        cout << y;
    }
}
int n, m, fz[200], fm[100];
int main() {
	freopen("fenshu.in", "r", stdin);
	freopen("fenshu.out", "w", stdout);
	cin >> n >> m;
	LL p = 1, q = 0;
	for(int i = 1; i <= n; i ++) {
		cin >> fz[i] >> fm[i];
	}
	for(int i = 1; i <= n; i ++) {
		LL l = lcm(p, fm[i]);
		q = q * (l / p);
		q = q + (l / fm[i]) * fz[i];
		p = l;
		LL t = gcd(p, q);
		p /= t;
		q /= t;
	}
	for(int i = 1; i <= m; i ++) {
		int x;
		cin >> x;
		p *= x;
	}
	LL t = gcd(p, q);
		p /= t;
		q /= t;
	if(p == 1) {
		print(q);
		return 0;
	}
	print(q);
	cout << ' ';
	print(p);
}