function solve(input) {
    let result = []
    let letter = ""
    class Catalogue {
        constructor(name, price) {
            this.name = name,
                this.price = price
        }
        letterFirst() {
            // let letter = ""
            this.name.charAt(0).toUpperCase() === letter ?
                console.log(`  ${this.name}: ${this.price}`)
                : (letter = this.name.charAt(0).toUpperCase(),
                    console.log(letter),
                    console.log(`  ${this.name}: ${this.price}`))
        }
    }
    input.map(x => {
        let [name, price] = x.split(" : ")
        let myCatalogue = new Catalogue(name, price)
        result.push(myCatalogue)
    })
    result.sort((a, b) => a.name.localeCompare(b.name))
        .forEach(x => x.letterFirst())
}