#include using namespace std; using vi = vector; using vvi = vector; using vvvi = vector; using ll = long long int; using vll = vector; using vvll = vector; using vvvll = vector; using vd = vector; using vvd = vector; using vvvd = vector; using P = pair; using Pll = pair; using cdouble = complex; const double eps = 1e-9; const double INFD = numeric_limits::infinity(); const double PI = 3.14159265358979323846; #define Loop(i, n) for(int i = 0; i < (int)n; i++) #define Loopll(i, n) for(ll i = 0; i < (ll)n; i++) #define Loop1(i, n) for(int i = 1; i <= (int)n; i++) #define Loopll1(i, n) for(ll i = 1; i <= (ll)n; i++) #define Loopr(i, n) for(int i = (int)n - 1; i >= 0; i--) #define Looprll(i, n) for(ll i = (ll)n - 1; i >= 0; i--) #define Loopr1(i, n) for(int i = (int)n; i >= 1; i--) #define Looprll1(i, n) for(ll i = (ll)n; i >= 1; i--) #define Foreach(buf, container) for(auto buf : container) #define Loopdiag(i, j, h, w, sum) for(int i = ((sum) >= (h) ? (h) - 1 : (sum)), j = (sum) - i; i >= 0 && j < (w); i--, j++) #define Loopdiagr(i, j, h, w, sum) for(int j = ((sum) >= (w) ? (w) - 1 : (sum)), i = (sum) - j; j >= 0 && i < (h); j--, i++) #define Loopdiagsym(i, j, h, w, gap) for (int i = ((gap) >= 0 ? (gap) : 0), j = i - (gap); i < (h) && j < (w); i++, j++) #define Loopdiagsymr(i, j, h, w, gap) for (int i = ((gap) > (h) - (w) - 1 ? (h) - 1 : (w) - 1 + (gap)), j = i - (gap); i >= 0 && j >= 0; i--, j--) #define Loopitr(itr, container) for(auto itr = container.begin(); itr != container.end(); itr++) #define printv(vector) Loop(ex_i, vector.size()) { cout << vector[ex_i] << " "; } cout << endl; #define printmx(matrix) Loop(ex_i, matrix.size()) { Loop(ex_j, matrix[ex_i].size()) { cout << matrix[ex_i][ex_j] << " "; } cout << endl; } #define quickio() ios::sync_with_stdio(false); cin.tie(0); #define bitmanip(m,val) static_cast>(val) #define Comp(type_t) bool operator<(const type_t &another) const #define fst first #define snd second bool nearlyeq(double x, double y) { return abs(x - y) < eps; } bool inrange(int x, int t) { return x >= 0 && x < t; } bool inrange(vi xs, int t) { Foreach(x, xs) if (!(x >= 0 && x < t)) return false; return true; } ll rndf(double x) { return (ll)(x + (x >= 0 ? 0.5 : -0.5)); } ll floorsqrt(ll x) { ll m = (ll)sqrt((double)x); return m + (m * m <= x ? 0 : -1); } ll ceilsqrt(ll x) { ll m = (ll)sqrt((double)x); return m + (x <= m * m ? 0 : 1); } ll rnddiv(ll a, ll b) { return (a / b + (a % b * 2 >= b ? 1 : 0)); } ll ceildiv(ll a, ll b) { return (a / b + (a % b == 0 ? 0 : 1)); } ll gcd(ll m, ll n) { if (n == 0) return m; else return gcd(n, m % n); } ll lcm(ll m, ll n) { return m * n / gcd(m, n); } /*******************************************************/ // n = 1.5e7 -> 80 ms vll list_prime_until(ll n) { vll ret; vector is_prime(n + 1, true); if (is_prime.size() > 0) is_prime[0] = false; if (is_prime.size() > 1) is_prime[1] = false; Loop(i, n + 1) { if (is_prime[i]) { ret.push_back(i); ll k = (ll)i * i; while (k < n + 1) { is_prime[int(k)] = false; k += i; } } } return ret; } // prime_list has to be generated by list_prime_until(>=sqrt(n)) vector prime_factorize(ll n, const vll &prime_list) { vector ret; Loop(i, prime_list.size()) { if (n == 1) break; while (n % prime_list[i] == 0) { if (ret.size() == 0 || ret.back().first != prime_list[i]) { ret.push_back({ prime_list[i], 0 }); } ret.back().second++; n /= prime_list[i]; } } if (n != 1) ret.push_back({ n, 1 }); return ret; } vll divisors(const vector factors) { queue que; que.push(1); Loop(i, factors.size()) { ll x = factors[i].fst, d = factors[i].snd; vll a(d + 1, 1); Loop1(j, d) a[j] = a[j - 1] * x; int m = int(que.size()); Loop(j, m) { ll y = que.front(); que.pop(); Loop(k, d + 1) que.push(y * a[k]); } } int m = int(que.size()); vll ret(m); Loop(i, m) { ret[i] = que.front(); que.pop(); } sort(ret.begin(), ret.end()); return ret; } int main() { int n; cin >> n; vll a(n); Loop(i, n) cin >> a[i]; sort(a.begin(), a.end()); vi dp(int(1e6) + 1); if (a[0] == 1) dp[1] = 1; vll primes = list_prime_until(int(1e3)); Loop(i, n) { vector facs = prime_factorize(a[i], primes); vll divs = divisors(facs); Loop(j, divs.size()) { if (divs[j] == a[i]) continue; dp[a[i]] = max(dp[a[i]], dp[divs[j]] + 1); } } int ans = 0; Loop(i, dp.size()) { ans = max(ans, dp[i]); } cout << ans << endl; }