N, X, T = list(map(int,input().split()))

counter = 0

rem = N

while rem > 0:

    rem -= X

    counter += 1

print((counter*T))

import math

N, X, T = list(map(int,input().split()))

if N%X == 0:

    print((int(N/X*T)))

else:

    print(((math.floor(N/X)+1)*T))
N, X, T = list(map(int, input().split()))
counter = 0
rem = N
while rem > 0:
    rem -= X
    counter += 1
print((counter * T))

import math

N, X, T = list(map(int, input().split()))
if N % X == 0:
    print((int(N / X * T)))
else:
    print(((math.floor(N / X) + 1) * T))

+import math + -counter = 0 -rem = N -while rem > 0: -    rem -= X -    counter += 1 -print((counter * T)) +if N % X == 0: +    print((int(N / X * T))) +else: +    print(((math.floor(N / X) + 1) * T))