A number theory problem by Abhijit Bhowmik

You are three brother,your mother make some no. of bread(roti). Now first you came you give one bread to your pet dog & then divide the remaining in three equal part, one part you ate other two part remains. Your younger two brother also do the same thing. And lastly your father came and ate all the remaining. What is the minimum no of Bread your mother have to make. **No bread will be cut.