ARRANGE

#include <iostream>
#include <cstdio>
#include <cstring>
#define task "ARRANGE"
using namespace std;
using ll = long long;
using ld = long double;

const int N = 1e3 + 5;
ll n, m, k;
ll f[N][N], a[N][N];

void Read(){
    cin >> n >> m >> k;
}

ll Cal(ll u, ll v){
    return (v - u + 1) * (v + u) / 2;
}

bool Check(ll v){
    ll p = max(v - k + 1, 1ll);
    ll q = max(1ll, v + k - n);
    return m - v >= Cal(p, v - 1) + Cal(q, v - 1);

}

void Solve(){
    ll l = 0, h = m;
    while(l <= h){
        ll m = (l + h) / 2;
        if(Check(m))
            l = m + 1;
        else
            h = m - 1;
    }
    cout << m - h << "\n";
}

main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0); if(fopen(task".INP", "r"))
    freopen(task".INP", "r", stdin),
    freopen(task".OUT", "w", stdout);
    int t;
    cin >> t;
    while(t--){
        Read();
        Solve();
    }
}