#include <bits/stdc++.h>
using namespace std;
int n,m,fenshu[3][55]={0};//1分子，2分母 
unsigned long long fz;
unsigned long long gcd(unsigned long long x,unsigned long long y)
{
    while(x!=y)
    {
        if(x<y)swap(x,y);
        x-=y;
    }
    return x;
}
int main()
{
    freopen("fenshu.in","r",stdin);
    freopen("fenshu.out","w",stdout);
    cin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        cin>>fenshu[1][i]>>fenshu[2][i];
    }
    for(int i=1;i<=m;i++)
    {
        cin>>fenshu[1][n+i];
        fenshu[2][n+i]=1;
    }
    unsigned long long Gcd=fenshu[2][1];
    for(int i=2;i<=n;i++)
    {
        Gcd=gcd(Gcd,fenshu[2][i]);
    }
    unsigned long long gbs=Gcd;
    for(int i=1;i<=n;i++)gbs*=fenshu[2][i]/Gcd;
    for(int i=1;i<=n;i++)
    {
        fz+=fenshu[1][i]*(gbs/fenshu[2][i]);
    }
    for(int i=1;i<=m;i++)gbs*=fenshu[1][n+i];
    unsigned long long g=gcd(fz,gbs);
    if(fz%gbs==0)cout<<fz/gbs<<endl;
    else
    {
        cout<<fz/g<<" "<<gbs/g<<endl;
    }
    return 0;
}