package main

import "fmt"

func main() {
	var a, b, n int
	var xn2, xn1, xn int
	xn1 = 1
	mod := int(1e9) + 7
	fmt.Scan(&a, &b, &n)
	if n == 0 {
		fmt.Println(0)
	} else if n == 1 {
		fmt.Println(1)
	} else {
		for i := 0; i < n-1; i++ {
			xn = ((a%mod)*(xn1%mod) + (b%mod)*(xn2%mod)) % mod
			// fmt.Printf("i %d, xn %d, xn1 %d, xn2 %d\n", i, xn, xn1, xn2)
			xn2 = xn1
			xn1 = xn
		}
		fmt.Println(xn)
	}
}