A, B, C = map(int, input().split())

ok = 1000000000000000000
ng = 0


def f(y):
    return y + (y // A) * (B - 1)


while ok - ng > 1:
    mid = (ok + ng) // 2
    if f(mid) >= C:
        ok = mid
    else:
        ng = mid

print(ok)