diff --git a/S2OJ/779/779.cpp b/S2OJ/779/779.cpp
new file mode 100644
index 00000000..3c04cf33
--- /dev/null
+++ b/S2OJ/779/779.cpp
@@ -0,0 +1,37 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int n, k, p, a, b, c, d, s[20000005], pre[20000005], suc[20000005], ans;
+
+int main() {
+    cin >> n >> k >> p;
+    cin >> a >> b >> c >> d;
+    s[1] = a;
+    for (int i = 2; i <= n; i++) {
+        s[i] = (1ll * s[i - 1] * b + c) % d;
+    }
+    for (int i = 1; i <= n; i++) {
+        if ((i - 1) % k) {
+            pre[i] = 1ll * pre[i - 1] * s[i] % p;
+        } else {
+            pre[i] = s[i];
+        }
+    }
+    for (int i = n; i > 0; i--) {
+        if (i % k) {
+            suc[i] = 1ll * suc[i + 1] * s[i] % p;
+        } else {
+            suc[i] = s[i];
+        }
+    }
+    for (int i = 1; i <= n - k + 1; i++) {
+        if ((i - 1) % k) {
+            ans ^= 1ll * suc[i] * pre[i + k - 1] % p;
+        } else {
+            ans ^= pre[i + k - 1];
+        }
+    }
+    cout << ans << endl;
+    return 0;
+}