function solve(arr) {
    //get the date from input and format it to fit the ISO standart
    var formattedDateFromInput = arr[0].split('-').reverse().join('-');
    var startDate = new Date(formattedDateFromInput);
    var endDate = addDays(startDate, 1000);
    var totalLeapYears = leapYearCheck(startDate, endDate);

    if (totalLeapYears != 0) {
        endDate = addDays(endDate, 0 - totalLeapYears);
    }
    //we have to reformat date now
    endDate = endDate.toISOString().replace(/T.*/, '').split('-').reverse().join('-');
    console.log(endDate);

    function addDays(date, days) {
        var result = new Date(date);
        result.setDate(result.getDate() + parseInt(days));
        return result;
    }

    // checks if the period contain leap year ( 1997-2001 checks 1997,8,9, 2000,1 if they are leap years);
    function leapYearCheck(startYear, finishedYear) {
        var z = 0;
        var yStarrt = startYear ? startYear.getUTCFullYear() : startYear.getFullYear();
        var yEnd = finishedYear ? finishedYear.getUTCFullYear() : finishedYear.getFullYear();
        var mStart = startYear.getMonth();
        var mEnd = finishedYear.getMonth();
        var dStart = startYear.getDate();

        //check if start year is a leap year,if yes adds one if it is before 29-02
        if ((yStarrt % 4 == 0) && (yStarrt % 100 != 0) || (yStarrt % 400 == 0)) {
            if (mStart <= 1) {
            }
            {
                z += 1
            }
        }
        //check if end year is a leap year,if yes adds one if it is after 29-02
        if ((yEnd % 4 == 0) && (yEnd % 100 != 0) || (yEnd % 400 == 0)) {
            if (mEnd > 1) {
            }
            {
                z += 1
            }
        }

        for (var i = yStarrt + 1; i < yEnd; i++) {
            if ((i % 4 == 0) && (i % 100 != 0) || (i % 400 == 0)) {
                z += 1;
            }
        }

        return z;
    }

}