#include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int n, k;     cin >> n >> k;     char def =  a ;     int pos = 0;     string ans =   ;     for (int i = 0; i < n; i++) {       ans += def + pos;       pos = (pos + 1) % k;     }     cout << ans;     return 0;   }   