v, t, p = map(int, input().split())


ng = 10 ** 20
ok = -1

while ng - ok > 1:
    mid = (ok + ng) // 2
    hanamizu = mid
    susuru = (mid - 1) // t
    hanamizu -= susuru
    if hanamizu <= (p + 1) * v:
        ok = mid
    else:
        ng = mid
    # print(ok, ng)
print(ng)