var s,t,w,n,i:integer; ch:array[1..26]of char;

procedure try(j,k:integer;c:char);

begin

if (ord(ch[j])+1-ord('a')>=k)and(j>1) then

begin

try(j-1,k-1,chr(ord(c)-1));

ch[j]:=chr(ord(ch[j-1])+1);

end

else ch[j]:=chr(ord(ch[j])+1);

end;

begin

readln(s,t,w);

for i:=1 to w do read(ch[i]);

n:=0;

while n<5 do

begin

inc(n);

try(w,t,chr(ord('a')+t-1));

if (ord(ch[1])+1-ord('a')>t-w+1) then break;

for i:=1 to w do write(ch[i]);

writeln;

end;

end.