import random
import functools

def iter_balanced_parens(num_pairs):
    if num_pairs == 0:
        yield ""
    else:
        for x in range(num_pairs):
            y = num_pairs - x - 1
            assert x + y == num_pairs-1
            for right in iter_balanced_parens(y):
                for left in iter_balanced_parens(x):
                    s = "(" + left + ")" + right
                    assert len(s) == 2 * num_pairs
                    yield s

for i in range(25):
    for s in iter_balanced_parens(i):
        print(s)