function companyUser(input){

let users= {}

input.forEach(line => {
    [company, employe] = line.split(" -> ")
    if(!users.hasOwnProperty(company)){
        users[company] = new Set()
    }
    users[company].add(employe)
});
let sorted = Array.from(Object.entries(users)).sort()
.forEach(key=>{
    console.log(key[0])
    for(let el of key[1]){
        console.log(`--`,el)
    }
})
}