#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define int long long
 
const int MOD = 1e9+7;
const int INF = LLONG_MAX/2;
 
signed main() {
   ios::sync_with_stdio(false); cin.tie(NULL);
   int t;
   cin >> t;
   while(t--) {
       long long a,b,n;
       cin >> a >> b>>n;
       vector<long long>x(n);
       for(int i=0;i<n;i++){
       	cin>>x[i];
       }
       long long maxtime=b;
       for(int i=0;i<n;i++){
       	maxtime+=min(x[i],a-1);
       }
       cout<<maxtime<<endl;
   }	   
}
 

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