#include <bits/stdc++.h>
#define int long long
#define ll long long
#define vi vector

using namespace std;

int32_t main() {
    int t;
    cin>>t;
    while (t--)
    {
ll n , d;
    cin>>n>>d;
    for(int i = 1 ; i < 65 ; i++){
        ll s = d - 1;
        ll p = 1;
        for(int j = 0;  j <  i ; j++) p*=2;
        s *= d - 1;
        s += p;
        if(s >= n){
            cout << i << "\n"; return 0;
        }
    }
    }
    
    
}