Python. 3 Lines.
\nclass Solution:\n    def isGoodArray(self, x: List[int]) -> bool:\n        g=x[0]\n        for i in x:g=gcd(i,g)\n        return g==1\n
```\nclass Solution:\n    def isGoodArray(self, x: List[int]) -> bool:\n        g=x[0]\n        for i in x:g=gcd(i,g)\n        return g==1\n```
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