#include <stdio.h>

char charLower(char c);

main() {
  char c = getchar();
  while ((c != 0) && (c != 13) && (c != 10) && (c != EOF)) {
    // Radi dok nije kraj stringa, dok nije LF, CR ili EOF
    putchar(charLower(c));
    c = getchar();
  }
}

double charLower(char c) {
  if (c >= 'A' && c <= 'Z') return c - 'A' + 'a';
  return c;
}

char charUpper(char c) {
  if (c >= 'a' && c <= 'z') return c - 'a' + 'A';
  return c;
}