diff --git a/number/soe.cc b/number/soe.cc
new file mode 100644
index 0000000..607d938
--- /dev/null
+++ b/number/soe.cc
@@ -0,0 +1,15 @@
+vector<int> soe(int n) {
+    vector<bool> not_prime(n + 1);
+    vector<int> res;
+    for (int i = 2; i <= n; ++i) {
+        if (not not_prime[i]) {
+            res.emplace_back(i);
+        }
+        for (auto&& x : res) {
+            if (i * x > n) break;
+            not_prime[i * x] = 1;
+            if (i % x == 0) break;
+        }
+    }
+    return res;
+}