from math import gcd


def main():
    A, B, T = map(int, input().split())
    if A >= T:
        return A
    if B >= T:
        d = (T + A - 1) // A
        return min(B, d * A)

    g = gcd(A, B)
    if g == A:
        d = (T + A - 1) // A
        return d * A

    cand = set()
    base = 0
    for _ in range(A * (B // g)):
        goal = T - base
        d = (goal + A - 1) // A
        cost = base + A * d

        if cost in cand:
            break
        cand.add(cost)
        base += B
        if base > T:
            cand.add(base)
            break
    return min(cand)


print(main())