function storeCatalogue(data){
let catalog = {}
data.forEach(line => {let [product,price]= line.split(" : ")
let firstLetter = product[0]
if(!catalog.hasOwnProperty(firstLetter))catalog[firstLetter] = {}
    catalog[firstLetter][product] = Number(price)

});
let sorted = Object.keys(catalog).sort((a,b)=> a.localeCompare(b)).forEach(keys=> {console.log(keys)
let sortedProducts = Object.keys(catalog[keys]).sort((a,b)=> a.localeCompare(b)).forEach(product=>
    console.log(`  ${product}: ${catalog[keys][product]}`))
})
}