#include <stdio.h>
int main(){
    FILE *fp;
    fp = fopen("iobinary.txt", "wb");
    if(fp == NULL){
        printf("Error opening file\n");
        return 1;
    }
    int num = 0x12345678;
    fwrite(&num, sizeof(int), 1, fp);
    fclose(fp);
    fp = fopen("iobinary.txt", "rb");
    int num2;
    fread(&num2, sizeof(int), 1, fp);
    printf("%d\n", num2);
    fclose(fp);
    return 0;
}