var cs,s,min,a,b,t,aux,i,w,c,g:integer; m,n:real;
    f,e:text; ok:boolean;
    r,h,v,j:array [1..1001] of integer; x:array [1..1000] of real;

BEGIN
assign(f,'energii.in');reset(f);assign(e,'energii.out');rewrite(e);
readln(f,g);readln(f,w);c:=10001;min:=-1;

for i:=1 to g do
    begin
    readln(f,a,b);
    v[i]:=a;
    j[i]:=b;
    end;
for i:=1 to g do
    BEGIN
    a:=v[i];b:=j[i];
    if (a>=w) and (b<c) then
       begin
        c:=b;
        min:=a;
       end;
    if a<w then
    BEGIN
     r[i]:=a;
     h[i]:=b;
    END;
 END;

 -----------------------------------------
if min=-1 then
for i:=1 to g do
   x[i]:=h[i] div r[i];
 -------------------------------

if min>=w then write (e,c) else write (e,cs);
close(f);close(e);
end.