Program soa_so;
Uses crt;
Var i,j,k,l,n:longint;
st2:string;
Begin
Clrscr;
write('nhap n,k:');readln(n,k);
str(n,st2);k:=length(st2)-k;
For i:=1 to k do
Begin
l:=i;
For j:=i to length(st2)k do
If st2[l]<st2[j] then l:=j;
If l>i then delete(st2,i,l-i);
End;
Write(copy(st2,1,k));
Readln;
End.