#include<stdio.h>
main(){
    char S[101];
    scanf("%s",S);
    int dif = 'a' - 'A';
    for(int i = 0;S[i] != '\0';i++){
        if(S[i] >= 'A' && S[i] <= 'Z'){
            printf("%c",S[i] + dif);
        }else{
            printf("%c",S[i] - dif);
        }
    }
    printf("\n");
}