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;
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize ("-ffloat-store") // to restrict undesirable precision
#pragma GCC optimize ("-fno-defer-pop")// to pop argument of function as soon as it returns
#define all(a) a.begin(),a.end()
#define ll long long int
#define ld long double
ll power(ll a,ll b,ll m){ if(b==0) return 1; if(b==1) return a%m; ll t=power(a,b/2,m)%m; t=(t*t)%m; if(b&1) t=((t%m)*(a%m))%m; return t;}
ll modInverse(ll a, ll m) { return power(a, m-2, m); }
#define ps push_back
#define fs first
#define takeline cin.ignore();
#define sc second
#define N 3000005
#define endl "\n"
#define mod 1000000007
//((1.0l)*BIG MULTIPLY MAGIC?)
// string to integer stoi()
// string to long long stoll()
// string.substr(position,length);
// integer to string to_string();
//-----------------------------------------------
int main(){

	ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
	
	ll a,b;
	cin>>a>>b;
	if(b<a){
		cout<<"0";return 0;
	}
	ll l,r,mid,an;
	l=1; r=1e10;
	while(r>=l){
		mid=(l+r)/2;

		ll c=a*mid;
		if(c>=b){
			an=mid;
			r=mid-1;
		}
		else l=mid+1;
	}
	cout<<an;
	return 0;
}