题解 | #自守数#

const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;

void async function () {
    // Write your code here
    let line = await readline()
    line = Number(line)
    let res = 0
    for (let i = 0; i <= line; i++) {
        let tmp = String(i * i)
        if (tmp.substring(tmp.length - String(i).length) === String(i)) {
            res++
        }
    }
    console.log(res)
}()