from flask import Flask
app = Flask(__name__)

letters = set()

@app.route('/')
def hello():
    return "Hello World!"


@app.route('/l/<l>')
def add_letter(l):
    letters.add(l)
    return l

@app.route('/reset')
def reset():
    global letters
    letters = set()
    return 'reseted'

@app.route('/get_char')
def get_char():
    x = []
    for i in range(37,127):
        if str(i) not in letters:
            x += [str(i)]
    return ','.join(x)
            

if __name__ == '__main__':
    app.run(host="0.0.0.0", port=81)