2036B.cpp

// coded by Cocane

#include<bits/stdc++.h>

#define ll long long
#define forn(i, n) for(int i = 0; i < n; i++)
#define for1(i, n) for(int i = 1; i <= n; i++)
#define foru(i, n) for(int i = n-1; i >= 0; i--)
#define fi first
#define se second
#define all(x) (x).begin(),(x).end()
#define allp(x) (x).begin(), (x).begin() + (x).size()/2, (x).rbegin()
#define pb push_back
#define ppb pop_back
#define read(a) for(auto &i: a) cin >> i
#define out(ans) cout<<ans<<endl
#define yn(a) cout<< (a ? "YES": "NO") <<endl

using namespace std;

typedef vector<int> vi;
typedef vector<ll> vll;
typedef double dl;


int main(){
		ios::sync_with_stdio(false);
		cin.tie(NULL);

		int t;
		cin>>t;
		while(t--){
				int n, k;
        cin >> n >> k;

        map<int, vector<int>> toCost;
        for (int i = 0; i < k; ++i) {
            int b, c;
            cin >> b >> c;
            toCost[b].pb(c);
        }

        vector<int> total;
        for (auto &i : toCost) {
            int sum = 0;
            for (int j : i.second) {
                sum += j;
            }
            total.pb(sum);
        }

        sort(total.rbegin(), total.rend());

        ll mxErn = 0;
        for (int i = 0; i < min(n, (int)total.size()); ++i) {
            mxErn += total[i];
        }

        out(mxErn);
		}
		return 0;
}