#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;
	}
}

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

NQp6eXhlZGNiYQoxCnJpbQoyCmJhY2EKMQpheXp5Ynl6Y3kKMwpheWJ6YwozCg==

5
zyxedcba
1
rim
2
baca
1
ayzybyzcy
3
aybzc
3