var f,g:text;
    st:array [1..1000000] of longint;
    n:longint;
    m,k,i,x,y,j:longint;
begin
assign(f,'stergeri.in');
reset(f);
assign(g,'stergeri.out');
rewrite(g);
read(f,n,m,k);
for i:=1 to n do st[i]:=i;
for i:=1 to m do begin
                 read(f,x,y);
                 j:=x;
                 while j<=y do   begin
                                 if st[x]<>0 then       begin
                                                        st[x]:=0;
                                                        j:=j+1;
                                                        end;
                                 x:=x+1;
                                 end;
                 end;
j:=0;
for i:=1 to n do begin
                 if st[i]<>0 then j:=j+1;
                 if j=k then begin
                             write(g,st[i]);
                             break;
                             end;
                 end;
close(f);
close(g);
end.