a=int(input()) if a <= 2000: print(a) elif 2000 <= a <= 3000: b=0.8*a b=round(b,1) print(b) elif 3000 <= a <4000: b=0.7*a b=round(b,1) print(b) elif 4000 <=a: b=0.6*a b=round(b,1) print(b)