a = float(input()) b = 2000 c = 3000 d = 4000 if a >= b and a < c: a = a * 0.8 print(f"{a:.1f}") if a >= c and a < d: a = a * 0.7 print(f"{a:.1f}") if a >= d: a = a * 0.6 print(f"{a:.1f}") else: print(f"{a:.1f}")