var x,y,n,k,i,j:longint;
f,g:text;
q,m:byte;
a:array[1..32000] of word;
begin
assign(f,'stergeri.in');
reset(f);
assign(g,'stergeri.out');rewrite(g);
read(f,n);
read(f,m);
readln(f,k);
read(f,x);
readln(f,y);
for i:=1 to x-1 do a[i]:=i;
i:=x;
for j:=y+1 to n do
begin
a[i]:=j;
inc(i);
end;
q:=1;
repeat
read(f,x);
readln(f,y);
inc(q);
for i:=x to y do
for j:=x to n do
a[j]:=a[j+1];
until q=m;
write(g,a[k]);
close(f);
close(g);
end.