# Col 1: Time customer enters the line
# Col 2: Time required for customer checkout
# Col 3: Time customer leaves the store
# Col 4: Time spent waiting in line
1 1 2 0
2 4 6 0
3 4 7 0
5 2 9 2
7 10 17 0
8 20 29 1
10 2 31 19
11 1 32 20
