#include<stdio.h>
int main(void)
{
  char str[255];
  int i;
  scanf("%s",str);

  for(i=0;i<=255;i++){
    if(str[i]>=65&&str[i]<=90){
      str[i] = str[i] + 32;
    }
    else{
      if(str[i]>=97&&str[i]<=122){
      str[i] = str[i] - 32;
      }
    }
  }
  printf("%s\n",str);

  return 0;
}