var v:array[1..100000]of integer;
    n,i,j,k,m,a,b,o:longint;
    f:text;
begin
   assign(f,'stergeri.in');
   reset(f);
   read(f,n,m,k);
   for i:=1 to m do
   begin
   read(f,a,b);
   o:=0;
   j:=0;
   while j<a-1 do
   begin
   o:=o+1;
   if v[o]=0 then j:=j+1;
   end;
   while j<b do
   begin
   o:=o+1;
   if v[o]=0 then begin j:=j+1;
                        v[o]:=1;
                  end;
   end;
   end;
   j:=0;
   o:=0;
   close(f);
   assign(f,'stergeri.out');
   rewrite(f);
   while j<k do
   begin
   o:=o+1;
   if v[o]=0 then j:=j+1;
   end;
   writeln(f,o);
   close(f);
end.