The question below consists of a set of labelled sentences. These sentences, when properly sequenced form a coherent paragraph. Select the most logical order of  the sentences from the given options.
P. Picking up some small pebbles, and then dropping them into the pitcher.
Q. A crow was very thirsty and he felt as if he must die of thirst.
R. After some time an idea came to the thirsty crow and it was: