diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 0000000..4918a32
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "Learning"
+version = "0.1.0"
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..6119f2f
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "Learning"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000..b84f152
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,11 @@
+{ pkgs ? import <nixpkgs> {} }:
+
+pkgs.mkShell {
+  nativeBuildInputs = with pkgs; [
+    cargo
+    rustc
+    rustfmt
+    clippy
+    rust-analyzer
+  ];
+}
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..d6e144d
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,48 @@
+enum MATH {
+    ADD,
+    SUB,
+    MUL,
+    DEV,
+}
+
+struct Math {
+    a: i32,
+    b: i32,
+}
+
+impl Math {
+    fn init(a: i32, b: i32) -> Math {
+        return Math { a, b };
+    }
+
+    fn calculate(&self, operation: MATH) -> i32 {
+        match operation {
+            MATH::ADD => return self.a + self.b,
+            MATH::SUB => return self.a - self.b,
+            MATH::MUL => return self.a * self.b,
+            MATH::DEV => {
+                if self.b == 0 {
+                    return 0;
+                } else {
+                    return self.a / self.b;
+                }
+            }
+        }
+    }
+
+    fn reinit(&mut self, a: i32, b: i32) {
+        self.a = a;
+        self.b = b;
+    }
+}
+
+fn main() {
+    let operation: MATH = MATH::ADD;
+    let mut calculator: Math = Math::init(10, 4);
+
+    print!("ans: {}\n", calculator.calculate(operation));
+
+    calculator.reinit(32, 2);
+
+    println!("ans after reinit: {}", calculator.calculate(MATH::DEV));
+}