OJ太坑了！！1214

这题所谓只扫一遍的贪心的确有点***** 冒泡排序一样的扫，貌似就没问题了

var
n,x,y,i,s,t,j,max:longint;
a,b:array[1..1000]of longint;
procedure swap(var a,b:longint);
var c:longint;
begin
c:=a;
a:=b;
b:=c;
end;
procedure sort;
begin
for i:=1 to n-1 do
for t:=i+1 to n do
if (b[i]>b[t]) then begin swap(a[i],a[t]);swap(b[i],b[t]);end;
end;
begin
readln(n);
for i:=1 to n do begin
readln(x,y);
if x<y then begin
a[i]:=x;
b[i]:=y;
end
else begin
a[i]:=y;
b[i]:=x;
end;
end;
sort;
max:=-maxlongint;
for i:=1 to n do if a[i]>=max then begin max:=b[i]; inc(s); end;
writeln(s);
end.