diff --git a/.vscode/launch.json b/.vscode/launch.json
deleted file mode 100644
index 1b4f259..0000000
--- a/.vscode/launch.json
+++ /dev/null
@@ -1,29 +0,0 @@
-{
-    // 使用 IntelliSense 了解相关属性。 
-    // 悬停以查看现有属性的描述。
-    // 欲了解更多信息，请访问: https://go.microsoft.com/fwlink/?linkid=830387
-    "version": "0.2.0",
-    "configurations": [
-        {
-            "name": "g++.exe build and debug active file",
-            "type": "cppdbg",
-            "request": "launch",
-            "program": "${fileDirname}\\${fileBasenameNoExtension}.exe",
-            "args": [],
-            "stopAtEntry": false,
-            "cwd": "${workspaceFolder}",
-            "environment": [],
-            "externalConsole": false,
-            "MIMode": "gdb",
-            "miDebuggerPath": "D:\\Programs\\MSYS2\\mingw64\\bin\\gdb.exe",
-            "setupCommands": [
-                {
-                    "description": "为 gdb 启用整齐打印",
-                    "text": "-enable-pretty-printing",
-                    "ignoreFailures": true
-                }
-            ],
-            "preLaunchTask": "g++.exe build active file"
-        }
-    ]
-}
\ No newline at end of file
diff --git a/.vscode/settings.json b/.vscode/settings.json
deleted file mode 100644
index a625c37..0000000
--- a/.vscode/settings.json
+++ /dev/null
@@ -1,6 +0,0 @@
-{
-    "files.associations": {
-        "chrono": "cpp",
-        "type_traits": "cpp"
-    }
-}
\ No newline at end of file
diff --git a/.vscode/tasks.json b/.vscode/tasks.json
deleted file mode 100644
index 586c074..0000000
--- a/.vscode/tasks.json
+++ /dev/null
@@ -1,23 +0,0 @@
-{
-    "tasks": [
-        {
-            "type": "shell",
-            "label": "g++.exe build active file",
-            "command": "D:\\Programs\\MSYS2\\mingw64\\bin\\g++.exe",
-            "args": [
-                "-H",
-                "-Wall",
-                "-Winvalid-pch",
-                "-I${workspaceFolder}\\.vscode",
-                "-g",
-                "${file}",
-                "-o",
-                "${fileDirname}\\${fileBasenameNoExtension}.exe"
-            ],
-            "options": {
-                "cwd": "D:\\Programs\\MSYS2\\mingw64\\bin"
-            }
-        }
-    ],
-    "version": "2.0.0"
-}
\ No newline at end of file
diff --git a/TmplPatch_2019Nanjing/proof_of_inv_table.md b/TmplPatch_2019Nanjing/proof_of_inv_table.md
new file mode 100644
index 0000000..993ef26
--- /dev/null
+++ b/TmplPatch_2019Nanjing/proof_of_inv_table.md
@@ -0,0 +1,15 @@
+```cpp
+invT[1] = 1;
+for (int i = 2; i < N; i++)
+  invT[i] = (mod - mod / i) * invT[mod % i] % mod;
+```
+
+$$
+p=ax+b \\
+ax+b \equiv 0 \pmod p\\
+ab^{-1}+x^{-1} \equiv 0 \pmod p \\
+x^{-1} \equiv -ab^{-1} \pmod p \\
+x^{-1} \equiv -\left \lfloor \frac{p}{x} \right \rfloor (p\bmod x)^{-1} \pmod p \\
+x^{-1} \equiv (p-p/x) (p\bmod x)^{-1} \pmod p \\
+$$
+