#include <iostream>
#include <cstdlib>
#include <string>
using namespace std;

int main()
{
	//Each hexadecimal digit is an abbreviation for a series of four bits.
	//There are 16 possible hexadecimal digits.
		
	const string a[] {
		"0", //0000
		"1", //0001
		"2", //0010
		"3", //0001
		"4", //0100
		"5", //0101
		"6", //0110
		"7", //0111
		"8", //1000
		"9", //1001
		"A", //1010
		"B", //1011
		"C", //1100
		"D", //1101
		"E", //1110
		"F"  //1111
	};
		
	const int nbits {32};   //number of bits in an int on our machine
	const int n {2025};     //In binary, 00000000000000000000011111101001
	const int bitmask {15}; //In binary, 00000000000000000000000000001111
	
	//Output the bits of n as 8 hexadecimal digits.
	//The & bitmask gives us a result in which only the rightmost 4 bits of
	//shifted survive.

	for (int i {nbits - 4}; i >= 0; i -= 4) {   //loops 8 times
		const int shifted {n >> i};
		const int theBits {shifted & bitmask};
		cout << a[theBits]; //thebits is in the range 0 to 15 inclusive.
	}

	cout << "\n";
	return EXIT_SUCCESS;
}