diff --git a/TangDou/LuoGuBook/ZhiMuSanJiaoXing.cpp b/TangDou/51NOD/1909.cpp
similarity index 100%
rename from TangDou/LuoGuBook/ZhiMuSanJiaoXing.cpp
rename to TangDou/51NOD/1909.cpp
diff --git a/TangDou/51NOD/1926.cpp b/TangDou/51NOD/1926.cpp
new file mode 100644
index 0000000..96cf46b
--- /dev/null
+++ b/TangDou/51NOD/1926.cpp
@@ -0,0 +1,37 @@
+#include <bits/stdc++.h>
+using namespace std;
+typedef pair<int, int> PII;
+#define x first
+#define y second
+
+PII a[110];
+int n, L;
+
+vector<int> X, Y;
+
+int ans;
+int main() {
+    cin >> n >> L;
+    for (int i = 1; i <= n; ++i) {
+        cin >> a[i].x >> a[i].y;
+        X.push_back(a[i].x);
+        X.push_back(a[i].x - L); // 所有可能的左上角起点坐标(x,y) 必然满足x in X,y in Y
+        Y.push_back(a[i].y);
+        Y.push_back(a[i].y - L);
+    }
+
+    for (int i = 0; i < X.size(); i++)
+        for (int j = 0; j < Y.size(); j++) { // 枚举每个可能的左上角坐标
+            int cnt = 0;
+            int x = X[i], y = Y[j];
+            for (int k = 1; k <= n; k++) // 枚举每个金矿
+                if (a[k].x >= x && a[k].x <= x + L && a[k].y >= y && a[k].y <= y + L)
+                    cnt++;
+
+            ans = max(ans, cnt);
+        }
+
+    cout << ans << endl;
+
+    return 0;
+}
\ No newline at end of file
diff --git a/TangDou/LuoGuBook/ZhiMuSanJiaoXing.in b/TangDou/51NOD/ZhiMuSanJiaoXing.in
similarity index 100%
rename from TangDou/LuoGuBook/ZhiMuSanJiaoXing.in
rename to TangDou/51NOD/ZhiMuSanJiaoXing.in
diff --git a/TangDou/51NOD/字母三角形.ggb b/TangDou/51NOD/字母三角形.ggb
new file mode 100644
index 0000000..9573358
Binary files /dev/null and b/TangDou/51NOD/字母三角形.ggb differ