#include <bits/stdc++.h>
using namespace std;
string zshiliu(int u) {
    char q, p;
    string s = "";
    if (u / 16 >= 10)
        p = 'A' + u / 16 - 10;
    else
        p = '0' + u / 16;
    s += p;
    if (u % 16 >= 10)
        q = 'A' + u % 16 - 10;
    else
        q = '0' + u % 16;
    s += q;
    return s;
}
int zshi(string s) {
    int a = 0;
    if (s[0] >= 'A' && s[0] <= 'F')
        a = (s[0] - 'A' + 10) * 16;
    else if (s[0] >= '0' && s[0] <= '9')
        a = (s[0] - '0') * 16;

    int b = 0;
    if (s[1] >= 'A' && s[1] <= 'F')
        b = (s[1] - 'A' + 10);
    else if (s[1] >= '0' && s[1] <= '9')
        b = (s[1] - '0');

    return a + b;
}

int main() {
    cout << zshiliu(10) << endl;
    cout << zshi("FF") << endl;
    cout << zshi("AA") << endl;
    return 0;
}