const oo=;

 var q,a,b,c,d:array[..]of int64;

     n,m,i,ans,t,w:longint;

     s:int64;

 procedure swap(var x,y:int64);

 var t:int64;

 begin

  t:=x; x:=y; y:=t;

 end;

 procedure qsort(l,r:longint);

 var i,j:longint;

     mid1,mid2,mid3:int64;

 begin

  i:=l; j:=r; mid1:=a[(l+r)>>]; mid2:=b[(l+r)>>]; mid3:=c[(l+r)>>];

  repeat

   while (mid1<a[i])or(mid1=a[i])and(mid2>b[i])or

         (mid1=a[i])and(mid2=b[i])and(mid3>c[i]) do inc(i);

   while (mid1>a[j])or(mid1=a[j])and(mid2<b[j])or

         (mid1=a[j])and(mid2=b[j])and(mid3<c[j]) do dec(j);

   if i<=j then

   begin

    swap(a[i],a[j]); swap(b[i],b[j]); swap(c[i],c[j]);

    inc(i); dec(j);

   end;

  until i>j;

  if l<j then qsort(l,j);

  if i<r then qsort(i,r);

 end;

 function min(x,y:longint):longint;

 begin

  if x<y then exit(x);

  exit(y);

 end;

 procedure shiftup(x,m:longint);

 begin

  while (x>)and(q[x]<q[x>>]) do

  begin

   swap(q[x],q[x>>]);

   x:=x>>;

  end;

 end;

 procedure shiftdown(x,m:longint);

 var t:longint;

 begin

  while (x<<)<=m do

  begin

   t:=x<<;

   if (t+<=m)and(q[t]>q[t+]) then t:=t+;

   if q[x]>q[t] then

   begin

    swap(q[x],q[t]);

    x:=t;

   end

    else break;

  end;

 end;

 begin

  //assign(input,'cf725D.in'); reset(input);

  //assign(output,'cf725D.out'); rewrite(output);

  readln(n);

  for i:= to n do

  begin

   read(a[i],b[i]);

   c[i]:=i;

  end;

  qsort(,n);

  for i:= to n do d[c[i]]:=i;

  for i:= to d[]- do

  begin

   inc(m); q[m]:=b[i]-a[i]+; shiftup(m,m);

  end;

  s:=a[d[]];

  for i:= to d[] do

   if a[i]>a[d[]] then inc(ans);

  inc(ans); t:=ans;

  w:=d[]+;

  while m> do

  begin

   if s-q[]>= then

   begin

    s:=s-q[]; q[]:=oo; shiftdown(,m); dec(t);

    while (w<=n)and(a[w]>s) do

    begin

     inc(m); q[m]:=b[w]-a[w]+; shiftup(m,m);

     inc(w); inc(t);

    end;

    ans:=min(ans,t);

   end

    else break;

  end;

  writeln(ans);

  //close(input);

  //close(output);

 end.