function main(input) {
    const args = input.split(" ");

    var No = parseInt(args[0], 10);
    var Earlier_No = parseInt(args[0].slice(1), 10);

    var ans = 1;

    // Max桁 -1まで
    for (var i = 0; i < parseInt(Earlier_No.toString().length) - 1; i++) {
        if (i == parseInt(Earlier_No.toString().length) - 2) {
            ans = ans * 2;
        }
        else if (i == parseInt(Earlier_No.toString().length) -1) {
            break;
        }
        else {
            ans = ans* 3;
        }
    }

    var puls_ans = 0;
    var is753 = /^[753][753]*[753]$/;

    var flag_7 = false;
    var flag_5 = false;
    var flag_3 = false;

    var start_no = parseInt(args[0].slice(0, 1), 10) * Math.pow(10, (args[0].length - 1));

    for(; start_no < No; start_no++){
        if(is753.test(start_no.toString())) {
            start_no = start_no.toString();
            flag_7 = start_no.indexOf('7') !== -1;
            flag_5 = start_no.indexOf('5') !== -1;
            flag_3 = start_no.indexOf('3') !== -1;
            if (flag_7 && flag_5 && flag_3) {
                puls_ans++;
            }
        }
    }

    console.log(puls_ans + ans);
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));