"""
[25704: 출석 이벤트](https://www.acmicpc.net/problem/25704)
Tier: Bronze 4
Category: 구현
"""
def solution():
n = int(input())
p = int(input())
l = [p]
if n >= 5:
l.append(p - 500)
if n >= 10:
l.append(p * 9 // 10)
if n >= 15:
l.append(p - 2000)
if n >= 20:
l.append(p * 3 // 4)
return max(0, min(l))
if __name__ == '__main__':
print(solution())