var k,i,j:integer; c: char;
s,t,answer: string;

begin
readln(k);
readln(s);

t:='';
for c:='a' to 'z' do begin
    
    j:=0;
    for i:=1 to length(s) do begin
        if c=s[i] then j:=j+1;
    end;

    while (j mod k = 0) and( j>0) do begin  t:=t+c; j:=j-k end;
    if (j mod k <> 0) and( j>0) then begin write(-1);exit end;
    
end;

answer:='';
while k>0 do begin 
    answer:=answer+t; 
    k:=k-1 
end;

writeln(answer);

end.