/* Copyright (c) 2026 Meng Zhuo */
/* SPDX-License-Identifier: BSD-3-Clause */
#include "stdio.h"
int main(void) {
int c = getchar();
if (c != 'h') return 1;
char buf[8];
if (fgets(buf, sizeof(buf), stdin) == NULL) return 2;
if (buf[0] != 'i' || buf[1] != '\n' || buf[2] != 0) return 3;
c = fgetc(stdin);
if (c != 'x') return 4;
if (ungetc(c, stdin) != c) return 5;
if (fgetc(stdin) != c) return 6;
char big[4];
size_t n = fread(big, 1, sizeof(big), stdin);
if (n != 3) return 7;
if (big[0] != 'y' || big[1] != '\n' || big[2] != 'z') return 8;
puts("stdio input ok");
return 0;
}