var f,g:text; n,m,k,i,j,x,y:longint; v:array[1..10000] of word;
begin
assign(f,'stergeri.in');reset(f);
assign(g,'stergeri.out');rewrite(g);
read(f,n,m,k);
for i:=1 to n do v[i]:=i;
for i:=1 to m do begin
read(f,x,y);
repeat
v[x]:=v[y+1];
x:=x+1;
y:=y+1;
until v[y+1]=0;
for j:=x+1 to y do v[i]:=0;
end;
write(g,v[k]);
close(f);
close(g)
end.