#include<stdio.h>

int main(void){
  int i;
  char S[100];
  scanf("%s", S);
  for(i = 0; S[i] != '\0'; i++){
    if('A' <= S[i] && S[i] <= 'Z') S[i] = 'a' + S[i] - 'A';
    else S[i] = 'A' + S[i] - 'a';
  }
  printf("%s\n", S);
  return 0;
}