#include <bits/stdc++.h>
using namespace std;

#define int int64_t
#define endl '\n'
#define pb push_back

void solve() {
	string s;
	int k;
	cin >> s >> k;
	int n = s.size();
	string ans;
	for(int i = 0; i < n; i++) {
		while(ans.size() && ans.back() < s[i] && k) {
			k--;
			ans.pop_back();
		}
		ans.pb(s[i]);
	}
	while(k--) ans.pop_back();
	cout << ans;
}

int32_t main() {
	int t = 1;
	cin >> t;
	while(t--) {
		solve();
		cout << endl;
	}
}