In each question, the first and the last sentences of the passage are numbered S1 and S6 respectively. The rest of the passage is split into four parts. These four sentences are jumbled. Read the sentences and identify their correct and logical order.

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S1: The commonest form of forgetfulness, I suppose, occurs in the matter of posting letters.
P: So common is it that I am always reluctant to trust a departing visitor to post an important letter.
Q: As for myself, anyone who asks me to post a letter is a poor judge of character.
R: Even if I carry the letter in my hand I am always past the first pillar box before I remember that I ought to have posted it.
S: So little I rely on his memory that I put him on his oath before handing the letter to him.
S6: Weary of holding it in my hand, I then put it for safety into one of my pockets and forget all about it.
The Proper sequence should be: