/////////////////////////////////No.311 z in FizzBuzzString 
    //入力文字読み取り
 var inputall = require('fs').readFileSync('/dev/stdin', 'utf8');

    //すべて受け取り数値化
    var inputnumber = Number(inputall);

    //3の倍数
    var three = Math.floor(inputnumber / 3);

    //５の倍数
    var five = Math.floor(inputnumber / 5);

    //ｚの個数を求める
    var result = Math.floor( (three + five) * 2);

    console.log(result);