program peste;
type fishp=record
           p,t:word;
           end;
var f:text;
    k,n,tt,i,maxp,nt,j,nr:longint;
    e:extended;
    v,vp:array[1..50000] of fishp;
    t:array[1..1000] of word;
    c:array[1..1000] of longint;
    l:array[1..50000] of extended;
    ctrl:boolean;

procedure qsort(bal,jobb:word);
var i,j,va:word;
    cs:fishp;
begin
     i:=bal;j:=jobb;
     va:=v[(i+j) div 2].t;
     while(i<=j) do
     begin
          while(v[i].t < va) do inc(i);
          while(v[j].t > va) do dec(j);
          if(i<=j) then
          begin
               cs:=v[i];
               v[i]:=v[j];
               v[j]:=cs;
               inc(i);dec(j);
          end;
     end;
     if(bal < j) then qsort(bal,j);
     if(i < jobb) then qsort(i,jobb);
end;

procedure qsortp(bal,jobb:word);
var i,j,va:word;
    cs:fishp;
begin
     i:=bal;j:=jobb;
     va:=vp[(i+j) div 2].p;
     while(i<=j) do
     begin
          while(vp[i].p > va) do inc(i);
          while(vp[j].p < va) do dec(j);
          if(i<=j) then
          begin
               cs:=vp[i];
               vp[i]:=vp[j];
               vp[j]:=cs;
               inc(i);dec(j);
          end;
     end;
     if(bal < j) then qsortp(bal,j);
     if(i < jobb) then qsortp(i,jobb);
end;

begin
     assign(f,'peste.in');
     reset(f);
     readln(f,n,k,tt);
     for i:=1 to n do
         readln(f,v[i].p,v[i].t);
     close(f);

     vp:=v;
     qsort(1,n);
     qsortp(1,n);

     i:=1;
     while(i<=n) do
     begin
          maxp:=i;
          while (i<n) and (v[i].t = v[i+1].t) do
          begin
               inc(i);
               if(v[i].p > v[maxp].p) then maxp:=i;
          end;
          inc(nt);
          t[nt]:=maxp;
          inc(i);
     end;

     for i:=1 to nt do
     begin
          j:=1;
          nr:=1;
          c[i]:=v[t[i]].p;
          ctrl:=false;
          while (nr<k) and (j<=n) do
          begin

               if (vp[j].t <= v[t[i]].t) and
                  ((v[t[i]].p <> vp[j].p) or ((v[t[i]].t) <> (vp[j].t)) or (ctrl)) then
               begin
                    inc(nr);
                    c[i]:=c[i]+vp[j].p;
               end;
               if(v[t[i]].p = vp[j].p) and (v[t[i]].t = vp[j].t) then ctrl:=true;

               inc(j);
          end;
     end;

     for i:=1 to nt do
         if(v[t[i]].t <= tt) then
         begin
              if(c[i] > l[v[t[i]].t]) then l[v[t[i]].t]:=c[i];
              if(l[v[t[i]].t] > e) then e:=l[v[t[i]].t];
         end;

     for i:=1 to tt do
     begin
          if(l[i] > 0) then
          begin
               for j:=1 to nt do
                   if(i+v[t[j]].t <= tt) then
                   begin
                        if(c[j]+l[i] > l[i+v[t[j]].t]) then l[i+v[t[j]].t]:=l[i]+c[j];
                        if(l[i+v[t[j]].t] > e) then e:=l[i+v[t[j]].t];
                   end;
          end;
     end;

     assign(f,'peste.out');
     rewrite(f);
     writeln(f,e:0:0);
     close(f);
end.