#include <ctype.h>

int isdigit(int c) {
  return (unsigned)c-'0' < 10;
}

int isxdigit(int c) {
  return isdigit(c) || ((unsigned)c|32)-'a' < 6;
}

int isblank(int c) {
  return (c == ' ' || c == '\t');
}

int isspace(int c) {
  return (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v');
}

int islower(int c) {
  return (unsigned)c-'a' < 26;
}

int isupper(int c) {
  return (unsigned)c-'A' < 26;
}

int isalpha(int c) {
  return isupper(c) || islower(c);
}

int isalnum(int c) {
  return isalpha(c) || isdigit(c);
}

int iscntrl(int c) {
  return (unsigned)c < 0x20 || c == 0x7f;
}

int isprint(int c) {
  return (unsigned)c-0x20 < 0x5f;
}

int isgraph(int c) {
  return (unsigned)c-0x21 < 0x5e;
}

int tolower(int c) {
  return isupper(c) ? (c | 32) : c;
}

int toupper(int c) {
  return islower(c) ? c & 0x5f : c;
}