function solve(input) {
    let friends = input[0].split(", ");

    for (let i = 1; i < input.length; i++) {
        let [command, value, newName] = input[i].split(" ");

        if (command === "Report") {
            break;
        } else if (command === "Blacklist") {
            if (friends.includes(value)) {
                let index = friends.indexOf(value);
                friends[index] = "Blacklisted";
                console.log(`${value} was blacklisted.`);
            } else {
                console.log(`${value} was not found.`);
            }
        } else if (command === "Error") {
            let userName = friends[value];
            if (userName !== "Blacklisted" && userName !== "Lost") {
                friends[value] = "Lost";
                console.log(`${userName} was lost due to an error.`);
            }
        } else if (command === "Change") {
            if (friends[value] !== undefined) {
                let currentName = friends[value];
                friends[value] = newName;
                console.log(`${currentName} changed his username to ${newName}.`);
            }
        }
    }

    let blacklistArr = friends.filter(e => e === "Blacklisted");
    let lostArr = friends.filter(e => e === "Lost");
    console.log(`Blacklisted names: ${blacklistArr.length}`);
    console.log(`Lost names: ${lostArr.length}`);
    console.log(friends.join(" "));
}