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>
#include <string>
#include <vector>
#include <algorithm>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <numeric>
#include <cmath>
#include <tuple>
#include <bitset>
#include <utility>
#include <climits>
#include <iomanip>

#define push emplace_back
#define each(i, x) for (auto i=0; i < x; i++)
using ull = unsigned long long;
constexpr auto mod = 1000000007;
constexpr auto INF = ULLONG_MAX;

using namespace std;
template <typename T> inline void dump(const T& x) { cout << "[" << x << "]" << endl; }
template <typename T> inline void dump(const vector<T>& x) { for (const auto v : x) { cout << v << " "; } cout << endl; }
template <typename T> inline void sort_asc(vector<T>& x) { std::sort(x.begin(), x.end()); }
template <typename T> inline void sort_desc(vector<T>& x) { std::sort(x.begin(), x.end(), greater<T>()); }
template <typename T> inline T max_value(vector<T>& x) { return *max_element(x.begin(), x.end()); }
template <typename T> inline T min_value(vector<T>& x) { return *min_element(x.begin(), x.end()); }
template <typename T> inline T sum_value(vector<T>& x) { return accumulate(x.begin(), x.end(), 0ULL); }

int main() {
  ull a, b;
  cin >> a >> b;

  each(i, 20) {
    ull count = i + 1;
    ull mouse = ((a-1) * count) + 1;
    if (mouse >= b) {
      cout << count << endl;
      return 0;
    } else {
      continue;
    }
  }

  return 0;
}