def f(mid):
    n = mid // A
    m = mid-n

    return n*B + m

A, B, C = list(map(int, input().split()))
l = 0
r = 10**18

while r-l > 1:
    mid = (l+r) // 2

    if f(mid) >= C: r = mid
    else: l = mid

if f(l) >= C: print(l)
else: print(r)