var p:array [1..20000000] of longint;
i,j,n,m,k,z,x,y,l:longint;
f,g:text;
begin
assign(f,'stergeri.in');
reset(f);
assign(g,'stergeri.out');
rewrite(g);
readln(f,n,m,k);
for i:=1 to n do begin
         p[i]:=i;
         end;
for i:=1 to m do begin
         read(f,x,y);
         j:=x;
         z:=0;
         while (z<=y-x) and (j<=n) do begin
                if p[j] <>-1 then begin
                             p[j]:=-1;
                             inc(z);
                             end;
                        inc(j);
         end;
end;
l:=0;
for i:=1 to n do begin
              if p[i]<>-1 then inc(l);
              if l=k then begin
                 write(g,p[i]);
                 break;
              end;
              end;
close(f);
close(g);
end.