#include <iostream>
using namespace std;
int main()
{
int n=100;
string r="01234567890ABCDEF";
string s="";
while (n>=1)
{
int k=n%16;
s = r[k]+s;
n=n/16;
}
cout << s << endl;
}
#include <iostream>
using namespace std;
int main()
{
int n=7;
string r="01";
string s="";
while (n>=1)
{
int k=n%2;
s = r[k]+s;
n=n/2;
}
cout << s << endl;
}