#include #include #include #include #include #include #include #include #include #include using namespace std; #define FOR(i,s,e) for (int i = int(s); i != int(e); i++) #define FORIT(i,c) for (typeof((c).begin()) i = (c).begin(); i != (c).end(); i++) #define ISEQ(c) (c).begin(), (c).end() int main(){ long N; cin >> N; string s = ""; N++; while(N!=0){ N--; char c = 'A' + N%26; s = s + c; N/=26; } cout << s << endl; return 0; }