program stergeri;
var ok:array[1..100000] of boolean;
    n,m,i,k:longint;
    st,stp:array[1..100000] of longint;
    da:boolean;

procedure citire;
var f:text;
begin
assign(f,'stergeri.in');
reset(f);
read(f,n,m,k);
fillchar(ok,m,true);
for i:=1 to m do
begin
readln(f);
read(f,st[i],stp[i]);
if st[i]<=k then
begin
ok[i]:=false;
k:=k+stp[i]-st[i]+1;
if k>n then
k:=n;
end;
end;
close(f);
end;


procedure afisare;
var g:text;
begin
assign(g,'stergeri.out');
rewrite(G);
write(g,k);
close(G);
end;

begin

citire;da:=true;
while da do
begin
da:=false;
for i:=1 to m do
if ok[i] and (st[i]<=k) then
begin
da:=true;
ok[i]:=false;
k:=k+stp[i]-st[i]+1;
if k>n then
k:=n;
end;
end;
afisare;
end.