Past week, i was asked this problem in an interview, i don't know the solution till now, help me with this.

# Problem

There are $$$N$$$ people in a group, weight of $$$i$$$ 'th person is $$$W[i]$$$, there is a lift of capacity $$$C$$$ which is the maximum weight the lift can carry, everyone wants to go to the top floor via lift.

Determine $$$M$$$, where $$$M$$$ is the minimum times lift must be used by the group so that everyone is able to go to the top floor.

## Constraints

Not sure about constraints, please give the best solution you can.

## Test Case

$$$N$$$ = 4

$$$C$$$ = 90

$$$W$$$ = [10, 20, 70, 80]

$$$ANS$$$ = 2