array filling problem code arrfill
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t;
cin >> t;
while(t--) {
ll n, m;
cin>>n>>m;
vector<pair<int,int>>vp;
for (int i=0; i < m; i++)
{
ll x, y;
cin>>x>>y;
vp.push_back({x,y});
}
sort(vp.begin(), vp.end(), greater<pair<int,int>>());
ll lcm=1;
ll rem=n;
ll res=0;
for (int i=0; i<m && rem>0; i++){
ll a= vp[i].first,b=vp[i].second;
lcm = lcm*b/__gcd(lcm,b);
res += (rem-n/lcm)*a;
rem= n/lcm;
}
cout <<res<<endl;
}
return 0;
}