# https://www.acmicpc.net/problem/17356
# boj, 17356: 욱 제, python3
import sys
input = sys.stdin.readline
def solve(a: int, b: int) -> float:
m = (b - a) / 400
return 1 / (1+10**m)
if __name__ == '__main__':
a, b = map(int, input().split()) # a: 욱의 욱제력, b: 제의 욱제력
print(solve(a, b))