【題解】AtCoder ABC 171C – One Quadrillion and One Dalmatians

#include <iostream>
using namespace std;

long long n;
string ans;

int main() {
    while (cin >> n){
        ans = "";
        while (n){
            ans = (char)('a'+((n-1+26)%26)) + ans;
            if (n % 26 == 0) n -= 26;
            n /= 26;
        }
        cout << ans << "\n";
    }
}