#include <iostream>
#include <string>
using namespace std;
int T,N;
string a;
int main()
{
cin>>T;
for(int t=0; t<T; t++)
{
cin>>N>>a;
for(auto iter=a.begin(); iter!=a.end(); ++iter)
{
if(*iter == 'c') N++;
else if(*iter == 'b') N--;
}
cout<<"Data Set "<<t+1<<":\n";
cout<<N<<"\n\n";
}
}