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 Python (3.8.2) (judge verdict: Runtime Error)

def main():

    n = int(input())
    db = []
    kinds = 0

    for i in range(10):
        tmp = []
        db.append(tmp)

    for i in range(n):
        str = input()
        num = len(str)

        if(not(str in db[num-1])):
            db[num-1].append(str)
            kinds = kinds + 1

    print(kinds)

main()