#include <stdio.h>
#include <string.h>

main()
{
    char in[20];
    
    printf("\nEnter Serial Number\n");
    scanf("%s", in);
    if(strncmp(in, "DEADBEEF", 8))
    {
        printf("Error! Incorrect serial number. Try again.\n");
    }
    else
    {
       printf("Serial number is correct.\n");
    }
}