#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
const int INF = 0x3f3f3f3f;
int n, dp[10005]; pair<int, int> p[10005];
signed main(void) {
	while (scanf("%d", &n), n) {
		for (int i = 1; i <= n; i++)scanf("%d%d", &p[i].first, &p[i].second);
		sort(p + 1, p + 1 + n); memset(dp, 0x3f3f3f3f, sizeof(dp));
		for (int i = 1; i <= n; i++)*upper_bound(dp, dp + n, p[i].second) = p[i].second;
		printf("%d\n", lower_bound(dp, dp + n, INF) - dp);
	}putchar('*');
}