# 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 10 3
11 1 12 0
5 2 13 6
7 10 23 6
8 20 43 15
10 2 45 33
