diff --git a/P6650.cpp b/P6650.cpp
new file mode 100644
index 0000000..08375e4
--- /dev/null
+++ b/P6650.cpp
@@ -0,0 +1,80 @@
+#include <bits/stdc++.h>
+using namespace std;
+int n, k;
+int a[100005];
+int spf[100005]; // 最小质因子
+vector<int> fac[100005]; // 每个数的质因子列表（带重数）
+int cnt[100005]; // 当前窗口内每个质数的总指数
+long long cur, ans;
+deque<int> dq_max, dq_min;
+// 计算e的贡献
+long long gx(int e) {
+    if (e == 0) return 0;
+    long long t = (sqrt(8.0 * e + 1) - 1) / 2;
+    while ((t + 1) * (t + 2) / 2 <= e) ++t;
+    while (t * (t + 1) / 2 > e) --t;
+    return e + t;
+}
+// 预处理最小质因子
+void init_spf() {
+    for (int i = 2; i < 100005; ++i) {
+        if (!spf[i]) {
+            spf[i] = i;
+            if ((long long)i * i < 100005) {
+                for (int j = i * i; j < 100005; j += i) {
+                    if (!spf[j]) spf[j] = i;
+                }
+            }
+        }
+    }
+}
+// 分解质因数
+void get_fac(int idx, int x) {
+    while (x > 1) {
+        int p = spf[x];
+        while (x % p == 0) {
+            fac[idx].push_back(p);
+            x /= p;
+        }
+    }
+}
+int main() {
+    scanf("%d%d", &n, &k);
+    init_spf();
+    for (int i = 1; i <= n; ++i) {
+        scanf("%d", &a[i]);
+        get_fac(i, a[i]);
+    }
+    int l = 1;
+    cur = 0,ans = 0;
+    for (int r = 1; r <= n; ++r) {
+        // 加入 a[r]
+        for (int p : fac[r]) {
+            int e = cnt[p];
+            cur += gx(e + 1) - gx(e);
+            cnt[p]++;
+        }
+        while (!dq_max.empty() && a[dq_max.back()] <= a[r]) dq_max.pop_back();
+        dq_max.push_back(r);
+        while (!dq_min.empty() && a[dq_min.back()] >= a[r]) dq_min.pop_back();
+        dq_min.push_back(r);
+        // 收缩左边界
+        while (1) {
+            while (!dq_max.empty() && dq_max.front() < l) dq_max.pop_front();
+            while (!dq_min.empty() && dq_min.front() < l) dq_min.pop_front();
+            int mx = a[dq_max.front()];
+            int mn = a[dq_min.front()];
+            if (mx - mn <= k) break;
+            // 移除 a[l]
+            for (int p : fac[l]) {
+                int e = cnt[p];
+                cur += gx(e - 1) - gx(e);
+                cnt[p]--;
+            }
+            l++;
+        }
+        ans = max(ans, cur);
+    }
+    printf("%lld\n", ans);
+    return 0;
+}
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