State what should be written in place of the labels L1, L2, and L3 in the algorithm below to successfully identify and output the item with the lowest stock level.

SUBROUTINE checkInventory(mode, totalItems)
    inventory ← [['Tablet', 'Laptop', 'Router', 'Switch', 'Phone'],
                 ['12', '4', '25', '8', '15']]
    pos ← 0
    low ← 9999
    IF mode = 'LOWEST' THEN
        FOR i ← 0 TO totalItems - 1
            stock ← STRING_TO_INT(inventory[L1][i])
            IF stock < low THEN
                low ← stock
                pos ← L2
            ENDIF
        ENDFOR
    ELSE
        OUTPUT 'not implemented'
    ENDIF
    IF low ≠ 9999 THEN
        OUTPUT inventory[0][pos], ' has stock level: ', inventory[1][pos]
    ENDIF
ENDSUBROUTINE

OUTPUT 'Search for HIGHEST or LOWEST stock? '
choice ← USERINPUT
checkInventory(L3, 5)

L1

L2

L3