**p, q**and

**r**such that the value of expression

**1/p+1/q+1/r**will be less than

**1/2**but as close to it as possible.

Find four distinct positive integers

**p, q, r**and

**t**such that the value of expression

**1/p+1/q+1/r+1/t**will be less than

**1**but as close to it as possible.