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<bits/stdc++.h>
using namespace std;

#define rep(i,n) for(int i = 0;i < (int)(n);i++)
#define Rep(i,n,m) for(int i = (int)(n); i < (int)(m);i++)
#define rrep(i,n) for(int i = (int)(n); i > -1;i--)

#define ALL(V) (V).begin(),(V).end()
#define SORT(V) sort(ALL(V))

#define Yes(n) cout << ((n) ? "Yes" : "No") << endl;
#define YES(n) cout << ((n) ? "YES" : "NO") << endl;

template<typename T>
void swap(T*,T*);

int main()
{
    int A,B;
    cin >> A >> B;
    int add = A - 1;
    int remain = B - A;
    cout << remain / add + 1 << endl;
}

template<typename T>
void swap(T* n,T* m)
{
    T tmp = *n;
    *n = *m;
    *m = tmp;
}