Ruby - T O(n), S O(1), 100% 100%
```\n# @param {String} s\n# @return {Integer}\ndef minimum_moves(s)\n  n = s.length\n  i = 0\n\n  result = 0\n  while i < n\n    if s[i] == \'X\'\n      i += 3\
```\n# @param {String} s\n# @return {Integer}\ndef minimum_moves(s)\n  n = s.length\n  i = 0\n\n  result = 0\n  while i < n\n    if s[i] == \'X\'\n      i += 3\n      result += 1\n    else\n      i += 1\n    end\n  end\n\n  result\nend
['Ruby']