100% faster kotlin easy solution
```\nclass Solution {\n    fun smallestRepunitDivByK(k: Int): Int {\n        if(k%2==0||k%5==0) return -1\n        var a=0\n        for(i in 1..k){\n           
```\nclass Solution {\n    fun smallestRepunitDivByK(k: Int): Int {\n        if(k%2==0||k%5==0) return -1\n        var a=0\n        for(i in 1..k){\n            a=(a*10+1)\n            if(a%k==0){\n                return i\n            }    \n            a%=k\n        }\n        return -1\n    }\n}
['Kotlin']