#include <bits/stdc++.h>   using namespace std;   struct edge {     int u, v;     long long w;   };   long long MOD = 1000000007;   long long _MOD = 1000000009;   double EPS = 1e-10;   long long c[100][100];   long long C(long long n, long long k) {     if (n < 100) return c[n][k];     long long ans = 1;     for (int i = 0; i < k; i++) ans *= n - i;     for (int i = 1; i <= k; i++) ans /= i;     return ans;   }   class NumberMagic {    public:     int theMin(int _N, int _M) {       if (_N == 1) return 0;       for (int i = 0; i < 100; i++) {         c[i][0] = 1;         for (int j = 1; j <= i; j++) c[i][j] = c[i - 1][j - 1] + c[i - 1][j];       }       long long N = _N, M = _M;       long long lb = 0, ub = N - 1;       while (ub - lb > 1) {         long long mid = (lb + ub) / 2;         long long n = N, sum = 0;         for (long long k = 0; k <= mid && n; k++) {           long long unko = min(n, C(mid, k));           n -= unko;           sum += k * unko;         }         if (!n && sum <= mid * M)           ub = mid;         else           lb = mid;       }       return ub;     }   };   int main() {     NumberMagic nm;     int T;     cin >> T;     while (T--) {       int N, M;       cin >> N >> M;       cout << nm.theMin(N, M) << endl;     }   }   