function plantbombs(){
        for(let i = 1; i <=  bomb; i++){
            let item = Square;
            let k = 0;
            let l = 0;
            do{
                k = Math.randomBetween(1, grid);
                l = Math.randomBetween(1, grid);
                item = matr[k][l];
            } while(item.num < 0);
            item.num = -10;
            item = matr[k-1][l];
            item.num += 1;
            item = matr[k+1][l];
            item.num += 1;
            item = matr[k][l-1];
            item.num += 1;
            item = matr[k][l+1];
            item.num += 1;

            item = matr[k-1][l-1];
            item.num += 1;
            item = matr[k+1][l-1];
            item.num += 1;
            item = matr[k-1][l+1];
            item.num += 1;
            item = matr[k+1][l+1];
            item.num += 1;

        }
    }