Problem:
Score : 100 points

Problem Statement

There are S sheep and W wolves.

If the number of wolves is greater than or equal to that of sheep, the wolves will attack the sheep.

If the wolves will attack the sheep, print unsafe; otherwise, print safe.

Constraints

1 \leq S \leq 100

1 \leq W \leq 100

Input

Input is given from Standard Input in the following format:

S W

Output

If the wolves will attack the sheep, print unsafe; otherwise, print safe.

Sample Input 1

4 5

Sample Output 1

unsafe

There are four sheep and five wolves. The number of wolves is not less than that of sheep, so they will attack them.

Sample Input 2

100 2

Sample Output 2

safe

Many a sheep drive away two wolves.

Sample Input 3

10 10

Sample Output 3

unsafe

Solution in C++ (GCC 9.2.1) (judge verdict: Accepted)

#define _USE_MATH_DEFINES
#include <iostream>
#include <vector>
#include <cmath>

using namespace std;

void abc_160a();

void abc_161a();

void abc_162a();

void abc_163a();

void abc_164a();

int main()
{
  //abc_160a();
  //abc_161a();
  //abc_162a();
  //abc_163a();
  abc_164a();


}

void abc_160a()
{
  string S;
  cin >> S;

  if (S[2] == S[3] && S[4] == S[5]) cout << "Yes\n";
  else cout << "No\n";
}

void swap(int& a, int& b)
{
  int tmp;
  tmp = a;
  a = b;
  b = tmp;
}

void abc_161a()
{
  int x, y, z;
  cin >> x >> y >> z;

  swap(x, y);
  swap(x, z);

  cout << x << " " << y << " " << z << "\n";
}

void abc_162a()
{
  string s;
  cin >> s;
  for (char c : s)
  {
    if (c == '7')
    {
      cout << "Yes\n";
      return;
    }
  }

  cout << "No\n";
}

void abc_163a()
{
  int R;
  cin >> R;

  cout << (double)(2 * R * M_PI);
}

void abc_164a()
{
  int s, w;
  cin >> s >> w;

  if (s <= w) cout << "unsafe\n";
  else cout << "safe\n";
}