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: Wrong Answer)

#include <iostream>
#define REP(i, n) for (int i = 0; i < (n); i++)
using namespace std;

void solve(long long A, long long B){
    if (A == B) cout << 1 << '\n';
    else if ((B-A) % (A-1)) cout << (B-A) / (A-1) + 2 << '\n';
    else cout << (B-A) / (A-1) + 1 << '\n';
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    long long A;
    scanf("%lld",&A);
    long long B;
    scanf("%lld",&B);
    solve(A, B);
    return 0;
}