///////// No.191 供託金
    process.stdin.resume();
    process.stdin.setEncoding('utf8');
    process.stdin.on('data', function (chunk) {

        //すべて受け取り改行で区切って格納
        var input = chunk.split("\n");
        //候補者数
        var candidate = Number(input[0]);
        //得票数
        var votes = input[1].split(" ").map(Number)

        var votestotal = 0;
        //有効投票総数
        for (var i = 0; i < candidate; i++) {
            votestotal += votes[i]
        }

        //供託金没収の人のカウント
        var fringecandidate = 0
        for (var j = 0; j < candidate; j++) {
            if (votestotal / 10 >= votes[j]) {
                fringecandidate++
            }
        }
        console.log(fringecandidate * 30)
    });