diff --git a/index.js b/index.js
index 7553909..2a99600 100644
--- a/index.js
+++ b/index.js
@@ -2,21 +2,39 @@ const CROSS = 'X';
 const ZERO = 'O';
 const EMPTY = ' ';
 
+let dimension;
+let emptyCellsCount;
+let curSymbol = CROSS;
+let hasWinner = false;
+let isGameOver = false;
+let grid;
+
 const container = document.getElementById('fieldWrapper');
 
 startGame();
 addResetListener();
 
 function startGame () {
-    renderGrid(3);
+    dimension = prompt('Введите размер поля:');
+    emptyCellsCount = dimension ** 2;
+    renderGrid(dimension);
+}
+
+function createEmptyGrid(dimension) {
+    grid = new Array(dimension);
+    for (let i = 0; i < dimension; i++) {
+        grid[i] = new Array(dimension);
+        for (let j = 0; j < dimension; j++)
+            grid[i][j] = EMPTY;
+    }
 }
 
 function renderGrid (dimension) {
+    createEmptyGrid(dimension);
     container.innerHTML = '';
-
-    for (let i = 0; i < dimension; i++) {
+    for (let i = 0; i < grid.length; i++) {
         const row = document.createElement('tr');
-        for (let j = 0; j < dimension; j++) {
+        for (let j = 0; j < grid.length; j++) {
             const cell = document.createElement('td');
             cell.textContent = EMPTY;
             cell.addEventListener('click', () => cellClickHandler(i, j));
@@ -27,18 +45,30 @@ function renderGrid (dimension) {
 }
 
 function cellClickHandler (row, col) {
-    // Пиши код тут
-    console.log(`Clicked on cell: ${row}, ${col}`);
-
-
-    /* Пользоваться методом для размещения символа в клетке так:
-        renderSymbolInCell(ZERO, row, col);
-     */
+    if (!hasWinner && !isGameOver && curSymbol === ZERO) {
+        randomZeroMove();
+        changeSymbol();
+        return;
+    }
+    if (!hasWinner && !isGameOver && grid[row][col] === EMPTY) {
+        grid[row][col] = curSymbol;
+        emptyCellsCount--;
+        renderSymbolInCell(curSymbol, row, col);
+        changeSymbol(); 
+        hasWinner = whoIsWinner();
+    }
+    if (hasWinner) {
+        isGameOver = true;
+        alert(hasWinner);
+    }
+    else if (isGameFinished()) {
+        isGameOver = true;
+        alert('Победила дружба!');
+    }
 }
 
 function renderSymbolInCell (symbol, row, col, color = '#333') {
     const targetCell = findCell(row, col);
-
     targetCell.textContent = symbol;
     targetCell.style.color = color;
 }
@@ -54,7 +84,83 @@ function addResetListener () {
 }
 
 function resetClickHandler () {
-    console.log('reset!');
+    curSymbol = CROSS;
+    isGameOver = false;
+    hasWinner = false;
+
+    startGame();
+    addResetListener();
+}
+
+const changeSymbol = () => curSymbol = curSymbol === CROSS ? ZERO : CROSS;
+
+const isGameFinished = () => emptyCellsCount === 0;
+
+function whoIsWinner() {
+    let verticalChecker = [];
+    const diagonalChecker1 = [];
+    const diagonalChecker2 = [];
+
+    for (let i = 0; i < grid.length; i++) {
+        if (new Set(grid[i]).size === 1 && !grid[i].some(item => item === EMPTY)) {
+            const winLine = [];
+            for (let j = 0; j < grid.length; j++)
+                winLine.push(i, j);
+            paintWinLine(winLine);
+            return grid[i][0];
+        }
+        diagonalChecker1.push(grid[i][i]);
+        diagonalChecker2.push(grid[i][grid.length - 1 - i]);
+        for (let j = 0; j < grid.length; j++)
+            verticalChecker.push(grid[j][i]);
+        if (new Set(verticalChecker).size === 1 && !verticalChecker.some(item => item === EMPTY)) {
+            const winLine = [];
+            for (let x = 0; x < grid.length; x++)
+                winLine.push(x, i);
+            paintWinLine(winLine);
+            return verticalChecker[0];
+        }
+        verticalChecker = [];
+    }
+
+    if (new Set(diagonalChecker1).size === 1 && !diagonalChecker1.some(item => item === EMPTY)) {
+        const winLine = [];
+        for (let i = 0; i < grid.length; i++)
+            winLine.push(i, i);
+        paintWinLine(winLine);
+        return diagonalChecker1[0];
+    }
+    else if (new Set(diagonalChecker2).size === 1 && !diagonalChecker2.some(item => item === EMPTY)) {
+        const winLine = [];
+        for (let i = 0; i < grid.length; i++)
+            winLine.push(i, grid.length - 1 - i);
+        paintWinLine(winLine);
+        return diagonalChecker2[0];
+    }
+    return false;
+}
+
+function paintWinLine(coords) {
+    for (let i = 0; i < coords.length; i += 2) {
+        findCell(coords[i], coords[i + 1]).style.color = 'red';
+    }
+}
+
+function randomZeroMove() {
+    const indexEmpty = Math.floor(Math.random() * emptyCellsCount);
+    const gridLine = grid.flat();
+    let index = 0;
+
+    for (let i = 0; i < gridLine.length; i++)
+        if (gridLine[i] === EMPTY) 
+            if (index++ === indexEmpty) {
+                const row = Math.floor(i / dimension);
+                const col = i % dimension;
+                grid[row][col] = ZERO;
+                renderSymbolInCell(ZERO, row, col);
+                emptyCellsCount--;
+                break;
+            }
 }