package main

import "fmt"

var A, B, C int64

func isSatisfied(years int64) bool {
	aYearNum := years / A
	if aYearNum == 0 || C - (years - aYearNum) + aYearNum - 1 <= 0 {
		return years >= C
	}

	return B >= (C - (years - aYearNum) + aYearNum - 1) / aYearNum
}

func main() {
	fmt.Scan(&A, &B, &C)

	var lb, ub int64 = 0, C + 1

	for ub - lb > 1 {
		mid := (ub + lb) / 2

		if isSatisfied(mid) {
			ub = mid
		} else {
			lb = mid
		}
	}
	fmt.Println(ub)
}