package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	r := bufio.NewReader(os.Stdin)
	S, _, _ := r.ReadLine()

	len := len(S)
	buf := make([]byte, len)

	for i := 0; i < len; i++ {
		if S[i] <= 'Z' {
			buf[i] = S[i] + 32
		} else {
			buf[i] = S[i] - 32
		}
	}
	fmt.Println(string(buf))
}