program pr;
uses crt;
var e,c,s:array [1..1001] of longint;
j,a,b,n,i,w,min:integer;
begin
clrscr;
readln(n);
readln(w);
for i:=1 to n do
readln(e[i],c[i]);
a:=0;
j:=0;
for i:=1 to n do
if e[i]=w then begin
a:=a+1;
j:=j+1;
s[j]:=c[i];
end;
min:=s[1];
for i:=1 to a do
if min>s[i] then min:=s[i];
writeln(min);
end.