var s:string;
    n,k,i,x:longint;
    t:char;
begin
    readln(n,k);
    s:='';
    for t:='a' to 'z' do
        s:=s+t;
    for i:=1 to k do
        write(s[i]);
    n:=n-k;
    x:=0;
    for i:=1 to n do
        begin
            if x mod 2 = 0  then    write(s[1])
                            else    write(s[2]);
            inc(x);
        end;
end.