题解 | #汽水瓶#

const readline = require('readline');

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
rl.on('line', function (line) {
    const emptyBottolesCount = parseInt(line);
    if (emptyBottolesCount === 0) return

    console.log(getDrinkCount(emptyBottolesCount, 0))
});

const getDrinkCount = (emptyCount, fillCount) => {
    if (emptyCount >= 3) {
        return getDrinkCount(emptyCount - 3 + 1, fillCount + 1)
    } else if (emptyCount === 2) {
        return fillCount + 1
    } else return fillCount
}