hdoj_1025

#include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
using namespace std;

const int maxn = 500000+5;
int a[maxn];
int d[maxn];
int N;
int temp;

int main() {
while(cin >> N) {
memset(d, 0, sizeof(d));
for(int i = 1; i <= N; i++) {
scanf("%d%d", &temp, &a[i]);
d[i] = 1;
}
for(int i = 2; i <= N; i++)
for(int j = 1; j < i; j++)
if(a[i] >= a[j])
d[i] = max(d[i], d[j]+1);
cout << *max_element(d+1, d+N+1)<< endl;
}
return 0;
}