Given a number of people and an array of integers which are umbrellas people capacity, return the min number umbrellas needed

umbrella.js

const sort = (list) => list.sort((a,b) => a < b)
const minus = (a) => (b) => a - b
const size = (list) => list.length
const obelus = (a) => (b) => Math.floor(a / b)
const times = (a) => (b)  => a  * b
const calc = (a) => (b) => minus(a)(times(b)(obelus(a)(b)))

const solve = (peoples) => (umbrellas) => {

    return sort(umbrellas).reduce((acc, cur, i) => {
        acc[1] += obelus(acc[0])(cur)
        acc[0] = calc(acc[0])(cur)

        if ((size(umbrellas) - 1) === i && acc[0] !== 0) acc[1] = -1

       return acc
    }, [peoples, 0])
}

const tests =
[ { n: 3
  , umbrellas: [1, 2]
  , expect: 2
  }
  
, { n: 10
  , umbrellas: [3, 1]
  , expect: 4
  }

, { n: 3
  , umbrellas: [2]
  , expect: -1
  }
]