题解 | #挑7#

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

void async function () {
    const n = parseInt(await readline());
    let cnt = 0;
    for(let i = 1; i <= n; i++){
        if(i%7===0 || String(i).indexOf(7)!=-1) cnt++;
    }
    console.log(cnt);
}()