#include <iostream>
int main()
{
char hex[16] = "FD";
int i = 0;
while(hex[i]) {
switch(hex[i]) {
case '0': std::cout << "0000"; break;
case '1': std::cout << "0001"; break;
case '2': std::cout << "0010"; break;
case '3': std::cout << "0011"; break;
case '4': std::cout << "0100"; break;
case '5': std::cout << "0101"; break;
case '6': std::cout << "0110"; break;
case '7': std::cout << "0111"; break;
case '8': std::cout << "1000"; break;
case '9': std::cout << "1001"; break;
case 'A': std::cout << "1010"; break;
case 'B': std::cout << "1011"; break;
case 'C': std::cout << "1100"; break;
case 'D': std::cout << "1101"; break;
case 'E': std::cout << "1110"; break;
case 'F': std::cout << "1111"; break;
case 'a': std::cout << "1010"; break;
case 'b': std::cout << "1011"; break;
case 'c': std::cout << "1100"; break;
case 'd': std::cout << "1101"; break;
case 'e': std::cout << "1110"; break;
case 'f': std::cout << "1111"; break;
default:
std::cout << "Error";
}
i++;
}
return 0;
}
/*
run:
11111101
*/