700 B | 700 chars
import sys
from math import sqrt, pi, sin, factorial, ceil, floor
from datetime import datetime, timedelta
BLANK = " "
# inp = input
inp = lambda : sys.stdin.readline()[:-1].strip()
mii = lambda x = BLANK : [*map(int,inp().split(x))]
mfi = lambda x = BLANK : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
p = print
def solve():
H, Y = mii()
D = [0] * (Y + 1)
D[0] = H
for i in range(1, Y + 1):
D[i] = max(D[i], D[i - 1] * 21 // 20)
if i > 2:
D[i] = max(D[i], D[i - 3] * 6 // 5)
if i > 4:
D[i] = max(D[i], D[i - 5] * 27 // 20)
p(D[Y])
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()