package main

import (
	"fmt"
	"unicode"
)

func inverse(s string) string {
	cs := []rune(s)
	for i := 0; i < len(cs); i++ {
		if unicode.IsUpper(cs[i]) {
			cs[i] = unicode.ToLower(cs[i])
		} else if unicode.IsLower(cs[i]) {
			cs[i] = unicode.ToUpper(cs[i])
		}
	}
	return string(cs)
}

func main() {
	var s string
	fmt.Scanf("%s", &s)

	fmt.Println(inverse(s))

}