An algorithm is designed to manage an automated greenhouse irrigation system.

1      humidity ← USERINPUT
2      status ← 'normal'
3      IF humidity < 30 THEN
4          status ← 'dry'
5      ELSE IF humidity > 70 THEN
6          status ← 'wet'
7      ENDIF
8      WHILE status = 'dry'
9          IF humidity < 15 THEN
10             OPEN_VALVE(2)
11         ELSE
12             OPEN_VALVE(1)
13         ENDIF
14         humidity ← USERINPUT
15     ENDWHILE

Which line number shows where selection is first used in the algorithm?