program stergeri;
type
tabel=array [0..200001] of longint;
var
t:tabel;
n,m,i,j,k,x,y,v:longint;
f1,f2:text;
begin
assign (f1,'stergeri.in');
assign (f2,'stergeri.out');
reset (f1);
rewrite (f2);
readln (f1,n,m,k);
for i:=1 to n do t[i]:=i;
for i:=1 to m do begin
readln (f1,x,y);
v:=0; j:=x-1;
repeat
j:=j+1;
if t[j]<>-1 then begin t[j]:=-1; v:=v+1; end;
until v=y-x+1;
end;
i:=0; j:=0;
repeat
i:=i+1;
if t[i]<>-1 then j:=j+1;
until j=k;
writeln (f2,t[i]);
close (f1);
close (f2);
end.