Maria baked 6 dozen cookies for her classmates. There are 28 students in her class, each child received 2 cookies and Maria gave 6 cookies each to her teacher and her principal. Which expression represents the number of cookies she had left over?
1) 6 x 12 - (28 x 2 + 6 + 6)
2) 6 x 12 - (28 x 2 - 6 - 6)
3) 6 x 12 - (28 x 2 - 6 + 6)
4) 6 x 12 - (28 x 2 + 6 - 6)