diff --git a/src/app.js b/src/app.js
index ad9a93a..12cad2c 100644
--- a/src/app.js
+++ b/src/app.js
@@ -1 +1,29 @@
+/* eslint-disable no-console */
 'use strict';
+
+const readline = require('readline');
+const { generateRandomNumber } = require('./generateRandomNumber.js');
+const { calculateBullsAndCows } = require('./calculateBullsAndCows.js');
+const { getInput } = require('./getInput.js');
+
+(async() => {
+  const currentNumber = generateRandomNumber();
+
+  while (true) {
+    const userInput = await getInput();
+
+    if (userInput.length !== 4) {
+      console.log('The number must consist of 4 characters');
+    }
+
+    const result = calculateBullsAndCows(currentNumber, userInput);
+
+    console.log(`Result: Bulls: ${result.bulls}, Cows: ${result.cows}`);
+
+    if (result.bulls === 4) {
+      console.log('Congratulations! You guessed the number.');
+
+      readline.close();
+    }
+  }
+})();
diff --git a/src/calculateBullsAndCows.js b/src/calculateBullsAndCows.js
new file mode 100644
index 0000000..dabb518
--- /dev/null
+++ b/src/calculateBullsAndCows.js
@@ -0,0 +1,21 @@
+'use strict';
+
+function calculateBullsAndCows(hiddenNumber, guessNumber) {
+  let bulls = 0;
+  let cows = 0;
+
+  for (const num in hiddenNumber) {
+    if (hiddenNumber[num] === guessNumber[num]) {
+      bulls++;
+    } else if (hiddenNumber.includes(guessNumber[num])) {
+      cows++;
+    }
+  }
+
+  return {
+    bulls,
+    cows,
+  };
+}
+
+module.exports = { calculateBullsAndCows };
diff --git a/src/generateRandomNumber.js b/src/generateRandomNumber.js
new file mode 100644
index 0000000..e126fd8
--- /dev/null
+++ b/src/generateRandomNumber.js
@@ -0,0 +1,17 @@
+'use strict';
+
+function generateRandomNumber() {
+  const digits = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+  let number = '';
+
+  for (let i = 0; i < 4; i++) {
+    const randomIndex = Math.floor(Math.random() * digits.length);
+    const digit = digits.splice(randomIndex, 1)[0];
+
+    number += digit;
+  }
+
+  return number;
+}
+
+module.exports = { generateRandomNumber };
diff --git a/src/getInput.js b/src/getInput.js
new file mode 100644
index 0000000..763e67b
--- /dev/null
+++ b/src/getInput.js
@@ -0,0 +1,18 @@
+'use strict';
+
+const readline = require('readline');
+
+function getInput() {
+  return new Promise((resolve) => {
+    const terminal = readline.createInterface({
+      input: process.stdin,
+      output: process.stdout,
+    });
+
+    terminal.question('Please, guess a number. ', (guessNumber) => {
+      resolve(guessNumber);
+    });
+  });
+}
+
+module.exports = { getInput };