1 + [a + [3 + [b + 4] + ב] + 2] + א
1 + [a + [3 + [b + 4] + ב] + 2] + א
1 + [a + [3 + [b + 4] + ב] + 2] + א
a + [1 + [b + [3 + ב] + 2] + א] + 0
a + [1 + [b + [3 + ב] + 2] + א] + 0
a + [1 + [b + [3 + ב] + 2] + א] + 0