#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

uint32_t read_be32(void) {
    uint32_t x = getchar();
    x = (x << 8) | getchar();
    x = (x << 8) | getchar();
    x = (x << 8) | getchar();
    return x;
}

int main(void) {
    // Test 0x02:
    putchar(0x02); putchar(0); putchar(0); putchar(0); putchar(46);
    printf("Hello World! Type the following string: 12345\n");
    // Test 0x01:
    putchar(0x01); if(getchar() != 0x1) exit(1);
    uint32_t x = read_be32();
    if(x != 0x0000005) exit(1);
    char buf[5]; fread(buf, 1, 5, stdin);
    if(buf[0] != '1' || buf[1] != '2' || buf[2] != '3' || buf[3] != '4' || buf[4] != '5') exit(1);
    // Test 0x03:
    putchar(0x03); putchar(0); putchar(0); putchar(0); putchar(7);
    printf("stderr\n");
    // Test 0x04, 0x05, 0x06:
    putchar(0x04); if (getchar() != 0x4) exit(1);
    int c = getchar();
    putchar(0x05); putchar(c); putchar(0x06); putchar(c);
    // Test 0x07:
    putchar(0x07); putchar(0); putchar(0); putchar(0); putchar(10); if (getchar() != 0x7) exit(1);
    x = read_be32();
    if(x != 0x000000a) exit(1);
    // Parrot it:
    char b2[10]; fread(b2, 1, 10, stdin);
    putchar(0x02); putchar(0); putchar(0); putchar(0); putchar(10);
    fwrite(b2, 1, 10, stdout);
    // Test 0x08:
}