package main

import (
	"fmt"
)

func main() {
	var sb, sa string
	var n int
	_, _ = fmt.Scan(&sb, &n, &sa)

	d := 0
	for i, c := range sb {
		if string(c) != string(sa[i]) {
			d++
		}
	}

	if d%2 != 0 {
		fmt.Println("SUCCESS")
		return
	}

	if (n-d/2)%2 == 0 {
		fmt.Println("FAILURE")
	} else {
		fmt.Println("SUCCESS")
	}
}