Problem:
Score : 200 points

Problem Statement

Takahashi's house has only one socket.

Takahashi wants to extend it with some number of power strips, each with A sockets, into B or more empty sockets.

One power strip with A sockets can extend one empty socket into A empty sockets.

Find the minimum number of power strips required.

Constraints

All values in input are integers.

2 \leq A \leq 20

1 \leq B \leq 20

Input

Input is given from Standard Input in the following format:

A B

Output

Print the minimum number of power strips required.

Sample Input 1

4 10

Sample Output 1

3

3 power strips, each with 4 sockets, extend the socket into 10 empty sockets.

Sample Input 2

8 9

Sample Output 2

2

2 power strips, each with 8 sockets, extend the socket into 15 empty sockets.

Sample Input 3

8 8

Sample Output 3

1

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

int main() {
  int a, b; cin >> a >> b;
  int origin = (b - 1 + a - 2) / (a - 1);
  int cur = 1;
  int cnt = 0;
  while(true) {
    if(cur * a >= b) {
      break;
    }
    cur *= a;
  }
  int has = (cur - 1) / (a - 1);
  for(int i = 0; i <= 50; i++) {
    if(i * (a - 1) >= b - cur and i <= cur) {
      assert(has + i == origin);
      cout << has + i << '\n';
      return 0;
    }
  }
}