#include <iostream>
using namespace std;
int t, n, a, c, b, y, x, najw;
int main()
{
ios_base::sync_with_stdio(0);
cin>>t;
while(t--)
{
najw=0;
y=1;
x=2;
cin>>n;
cin>>a;
if(n==1)
{
cout<<"1"<<endl;
continue;
}
cin>>b; n-=2;
while(a==b&&n!=0)
{
cin>>b;
x++;
y++;
}
if(!n)
{
cout<<x<<endl; continue;
}
while(n--)
{
cin>>c;
if(b==c)
{
x++;
y++;
}
else if(c==a)
{
y=1;
x++;
a=b;
b=c;
}
else
{
if(x>najw)
najw=x;
x=y+1;
y=1;
a=b;
b=c;
}
}
if(x>najw)
najw=x;
cout<<najw<<endl;
}
return 0;
}
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