/*
 * javascript bf interpreter
 * by wenxichang@163.com
 */

function execute(code)
{
    var mem = new Array(30000);
    var sp = 10000;
    var opcode = new String(code);
    var oplen = opcode.length;
    var ip = 0;
    var loopstack = new Array();
    var output = "";

    for (var i = 0; i < 30000; ++i) mem[i] = 0;

    while (ip < oplen) {
        switch(opcode[ip]) {
            case '+':
                mem[sp]++;
                break;
            case '-':
                mem[sp]--;
                break;
            case '>':
                sp++;
                break;
            case '<':
                sp--;
                break;
            case '.':
                if (mem[sp] != 10 && mem[sp] != 13) {
                    output = output + Util.fromCharCode(mem[sp]);
                } else {
                    puts(output);
                    output = "";
                }
                break;
            case ',':
                var s = console.input();
                if (!s) exit(0);

                mem[sp] = s.charCodeAt(0);
                break;
            case '[':
                if (mem[sp]) {
                    loopstack.push(ip);
                } else {
                    for (var k = ip, j = 0; k < oplen; k++) {
                        opcode[k] == '[' && j++;
                        opcode[k] == ']' && j--;
                        if (j == 0) break;
                    }
                    if (j == 0) ip = k;
                    else {
                        puts("Unmatched loop");
                        return false;
                    }
                }
                break;
            case ']':
                ip = loopstack.pop() - 1;
                break;
            default:
                break;
        }
        ip++;
    }
    return true;
};

if (Interp.conf('unitTest') > 0)  execute('
    ++++++++++[>+>+++>++++>+++++++ >++++++++>+++++++++>++++++++++>+++++++++
    ++>++++++++++++<<<<<<<<<-]>>>>+.>>>>+..<.<++++++++.>>>+.<<+.<<<<++++.<+
    +.>>>+++++++.>>>.+++.<+++++++.--------.<<<<<+.<+++.---.
');