#include<stdio.h>
    int main(){
        char s [100];
        scanf("%s", s);
            int i = 0;
                for(i = 0;s[i] != '\0'; i++){
                    if('a' <= s[i] && s[i] <= 'z'){
                        s[i] = s[i] - 32;
                    }else if('A' <= s[i] && s[i] <= 'Z'){
                        s[i] = s[i] + 32;
                    }}
            printf("%s\n", s);
        return 0;
    }