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 PyPy3 (7.3.0) (judge verdict: Runtime Error)

s = input()
n = s.__len__()
c = 0
l = list()
for i in range(n):
    l.append(s[i])
len = l.__len__()
for i2 in range(len):
    start = s[i2]
    for i3 in range(len-i2-1):
        start += s[i3+i2+1]
        if int(start) % 2019 == 0:
            c = c + 1
print(c)