The following six sentences come from a paragraph. The first and the last sentences are given. Choose the order in which the four sentences (PQRS) should appear to complete the paragraph.
S1 : The life of early men had advantages and disadvantages.
S6 : On the whole, there was friendship and amity within the tribes.
P : Then, they had enough physical exercise which made them healthy and active.
Q : They could roam for months without fear of meeting a stranger.
R : One of the advantages was that they were not overcrowded.
S : They lived in small tribes where everybody knew everybody else.
Select the correct sequence.