class InventoryManager:

def $\_\_$init$\_\_($self$)$:

self.inventory $=$ Inventory$()$

def run$($self$)$:

while True:

print$("$

Available commands:"$)$

print$("1.$ Add Item"$)$

print$("2.$ Remove Item"$)$

print$("3.$ View Inventory"$)$

print$("4.$ Exit"$)$

command $=$ input$("$Enter command: $")$

if command $=="1"$:

name $=$ input$("$Enter item name: $")$

quantity $=$ validated$\_$integer$\_$input$("$Enter quantity: $")$

self.inventory.add$\_$item$($Item$($name$,$ quantity$))$

elif command $=="2"$:

name $=$ input$("$Enter item name: $")$

quantity $=$ validated$\_$integer$\_$input$("$Enter quantity: $")$

self.inventory.remove$\_$item$($name$,$ quantity$)$

elif command $=="3"$:

self.inventory.view$\_$inventory$()$

elif command $=="4"$:

break

def validated$\_$integer$\_$input$($prompt$)$:

while True:

try:

return int$($input$($prompt$))$

except ValueError:

print$(\text{'}$Invalid input, please enter an integer.$\text{'})$