백준 4796

case = 0

while True:
    case = case + 1
    result = 0
    L, P, V = map(int, input().split())

    if L == 0 and P == 0 and V == 0:
        break
    else:
        if L < (V - P * (V // P)):
            result = (V // P * L) + L
        else:
            result = (V // P * L) + (V - P * (V // P))

        print("Case %d: %d" % (case, result))

# 반례 123 456 789 -> 246