#include <ctype.h>
#include <stdio.h>

int main(void){
  char s[150];
  int i;

  scanf("%s", s);

  for(i=0;s[i];i++){
    if(isupper(s[i])) printf("%c", tolower(s[i]));
    else printf("%c", toupper(s[i]));
  }

  printf("\n");

  return 0;
}