#include #include #include using namespace std; const int maxn = 5005; int a[maxn], dp[maxn]; int n; int rec(int at) { if(dp[at] != -1) { return dp[at]; } int res = 1; for(int i = at + 1; i < n; i++) { if(abs(a[at]) < abs(a[i])) { if((a[at] > 0 and a[i] < 0) or (a[at] < 0 and a[i] > 0)) { res = max(res, rec(i) + 1); } } } return dp[at] = res; } int main() { ios_base::sync_with_stdio(false); cin >> n; for(int i = 0; i < n; i++) { cin >> a[i]; dp[i] = -1; } int res = 0; for(int i = 0; i < n; i++) { res = max(res, rec(i)); } cout << res << endl; return 0; }