program Energii;
var g,w,i,k,cmin:integer;
   eg,cg,m,s:array[1..10000] of integer;
   t,f:text;
begin
assign(t,'energii.in');
assign(f,'energii.out');
reset(t);
rewrite(f);
readln(t,g);
readln(t,w);
for i:=1 to g do begin
                read(t,eg[i],cg[i]);
                while m[i]<>w do begin
                s[i]:=s[i]+cg[i];
                m[i]:=m[i]+eg[i];
                                  end;
end;
cmin:=s[1];
for i:=1 to g do if cmin>s[i] then cmin:=s[i];
writeln(f,cmin);
close(t);
close(f);
end.