#!/usr/bin/python2
# -*- coding: utf-8 -*-
# †
# age 歳のときに貰った総額
def f(age, a, b):
    loop = age / a
    per = a - 1 + b
    res = per * loop + (age % a)
    return res


a, b, c = map(int, raw_input().split())

# (lo, hi]
lo, hi = 0, 10**100
while hi - lo > 1:
    md = (lo + hi) / 2
    if f(md, a, b) >= c:
        hi = md
    else:
        lo = md
print hi