#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdint.h>
#define SIZE (1024*1024)

int main() {
	FILE *in = fopen("source", "r");
	FILE *out = fopen("cracked", "wb");
	char buffer[SIZE];
	size_t bytes;

	while (0 < (bytes = fread(buffer, 1, sizeof(buffer), in)))
		    fwrite(buffer, 1, bytes, out);
	fclose(in);
	fclose(out);

	out = fopen("cracked", "r+b");
	long int offset = 0x520;
	uint8_t new = 0xe0;

	fseek(out, offset, SEEK_SET);

	fputc(new, out);
	fclose(out);
	return 0;
}