#include <stdbool.h>

static unsigned int random_seed = 53455346;

int isupper(int c) { return (c >= 65 && c <= 90); }

int islower(int c) { return (c >= 97 && c <= 122); }

int toupper(int c) {
    if (!islower(c)) {
        return c;
    }

    return c - 32;
}

int tolower(int c) {
    if (!isupper(c)) {
        return c;
    }

    return c + 32;
}

int isdigit(int c) { return (c >= 48 && c <= 57); }

int isalpha(int c) { return (c >= 65 && c <= 90) || (c >= 97 && c <= 122); }

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

int iscntrl(int c) { return (c <= 31) || (c == 127); }

int isprint(int c) { return (c >= 32 && c <= 126) || (c >= 128 && c <= 254); }

int isgraph(int c) { return isprint(c) && c != 32; }

int ispunct(int c) { return isgraph(c) && !isalnum(c); }

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

int isxdigit(int c) {
    return isdigit(c) || (c >= 65 && c <= 70) || (c >= 97 && c <= 102);
}