Beats 95.59% / 64.74%. The most simple js solution
\nvar maximumNumberOfStringPairs = function(words) {\n    const set = new Set()\n    let cnt = 0\n    \n    for (let word of words) {\n        if (set.has(word.
```\nvar maximumNumberOfStringPairs = function(words) {\n    const set = new Set()\n    let cnt = 0\n    \n    for (let word of words) {\n        if (set.has(word.split(\'\').reverse().join(\'\'))) cnt++\n        \n        set.add(word)\n    }\n    \n    return cnt\n};\n```
['JavaScript']