#include <bits/stdc++.h>
#define int long long
#define H 19260817
#define rint register int
#define For(i,l,r) for(rint i=l;i<=r;++i)
#define FOR(i,r,l) for(rint i=r;i>=l;--i)
#define MOD 1000003
#define mod 1000000007
#define inf 1e6

using namespace std;

inline int read() {
  rint x=0,f=1;char ch=getchar();
  while(ch<'0'||ch>'9'){if (ch=='-') f=-1;ch=getchar();}
  while(ch>='0'&&ch<='9'){x=(x<<1)+(x<<3)+(ch^48);ch=getchar();}
  return x*f;
}

void print(int x){
  if(x<0){putchar('-');x=-x;}
  if(x>9){print(x/10);putchar(x%10+'0');}
  else putchar(x+'0');
  return;
}

const int N = 5100;

int n = read(), a[N], ans, maxi, f[N]; 

int dfs(int x) {//前x个数的最大长度ans 
	if(f[x] != -1) return f[x];
	int res = 1;
	for (int j = 1; j < x; j++) {
		if(a[j] < a[x]) res = max(res, dfs(j) + 1);
	}
	return f[x] = res;
}

signed main() {
	memset(f, -1, sizeof f);
	For(i,1,n) a[i] = read();
	a[n + 1] = inf; 
	cout << dfs(n) << '\n';
  return 0;
}