#include <bits/stdc++.h>
using namespace std;
int main() {
int t;
cin >> t;
while(t--)
{
int n,c=0,d=0;
cin >> n;
vector<int> v;
for(int i=0;i<n;i++)
{
int a;
cin >> a;
v.push_back(a);
}
for(int i=0;i<n-1;i++)
{
if((v[i]=='0' && v[i+1]== '1'))
{
c++;
}
else if((v[i]=='1' && v[i+1]== '0'))
{
d++;
}
}
int p = min(c,d);
cout << p << endl;
}
return 0;
}
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