if __name__ == '__main__':
    lines = [line.strip('\n') for i, line in enumerate(open('hashuri.in', 'r')) if i > 0]
    outputFile = open('hashuri.out', 'w')

    d = {}
    for line in lines:
        op, number = [int(intValue) for intValue in line.split()]

        if op == 1:
            d[number] = 1
        elif op == 2:
            if d.get(number, 0):
                del d[number]
        else:
            outputFile.write("%d\n" % d.get(number, 0))