#include <cstdio>
#include <cstring>
#include <cctype>
int main(){
    char S[101];
    scanf("%s",S);
    for(int i=0;i<strlen(S);i++){
        if(isupper(S[i]))S[i]=tolower(S[i]);
        else S[i]=toupper(S[i]);
    }
    printf("%s\n",S);
    return 0;
}