<strong>Input:</strong> s = "RLRRLLRLRL"
<strong>Output:</strong> 4
<strong>Explanation:</strong> s can be split into "RL", "RRLL", "RL", "RL", each substring contains same number of 'L' and 'R'.
<strong>Input:</strong> s = "RLRRRLLRLL"
<strong>Output:</strong> 2
<strong>Explanation:</strong> s can be split into "RL", "RRRLLRLL", each substring contains same number of 'L' and 'R'.
Note that s cannot be split into "RL", "RR", "RL", "LR", "LL", because the 2<sup>nd</sup> and 5<sup>th</sup> substrings are not balanced.</pre>