import sys
input = sys.stdin.readline


def main():
    def isOK(m):
        k = m//A
        money = (m - k) + (k * B)
        return money >= C


    def binary_search(ok, ng):
        while ok - ng > 1:
            mid = (ok + ng) // 2
            if isOK(mid):
                ok = mid
            else:
                ng = mid
        return ok
    

    A, B, C = map(int, input().split())
    
    ok = 10**18 + 1
    ng = 1
    print(binary_search(ok, ng))


if __name__ == '__main__':
    main()