fun f(a: Long, b: Long, c: Long): Long =
    when {
        a<=c -> {
            val d = a.dec()+b
            c/d*a + (if (c%d<a) c%d else a)
        }
        else -> c
    }

fun main(args: Array<String>) {
    val (a,b,c) = readLine()!!.split(' ').map(String::toLong)
    println(f(a,b,c))
}