#include <bits/stdc++.h>
using namespace std;
int hcf(int num1,int num2){
	int hcf;
	for(int i=1; i<=num1 || i<=num2; ++i)
    {
        if(num1%i==0 && num2%i==0)   /* Checking whether i is a factor of both number */
            hcf=i;
    }
    return hcf;
}
int main()
{
	int t,n,i,ans,k,r,p,q;
	scanf("%d",&t);
	while(t--){
		scanf("%d",&n);
		int a[n+5];
		ans=0;
		for(i=0;i<n;i++) scanf("%d",&a[i]);
		p=a[0];
		for(i=1;i<n;i++){
			r=hcf(p,a[i]);
			p=r;
		}
		if(r==1) printf("%d\n",n);
		else printf("0\n");
	}
	return 0;
}

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MwozCjMgNCA1CjQKMiA0IDYgOAo0CjIgMyA0IDgg

3
3
3 4 5
4
2 4 6 8
4
2 3 4 8