#include<bits/stdc++.h>
using namespace std;
constexpr int maxn=1e5+5;
string s[maxn];int a[maxn];
int ch[maxn][26],tot,val[maxn];
int cnt[maxn];
inline void solve(){
    int n;cin>>n;vector<int> v;
    for(int i=1;i<=n;i++) cin>>s[i]>>a[i],v.push_back(a[i]);
    sort(v.begin(),v.end());v.erase(unique(v.begin(),v.end()),v.end());
    memset(val,0,sizeof(int)*(tot+1));
    memset(ch,0,sizeof(ch[0])*(tot+1));tot=1;
    memset(cnt,0,sizeof(int)*(v.size()+1));
    for(int i=1;i<=n;i++){
        a[i]=lower_bound(v.begin(),v.end(),a[i])-v.begin()+1;
        cnt[a[i]]++;
        int p=1;
        for(auto x:s[i]){
            int&c=ch[p][x-'a'];
            if(!c) c=++tot;
            p=c;
        }
        if(val[p]){
            if(val[p]==a[i]) cnt[a[i]]--;
            else return cout<<"-1\n",void();   
        }
        val[p]=a[i];
    }
    int ans=0;
    for(int i=tot;i>=1;i--){
        unordered_map<int,int> mp;
        for(int x:ch[i])if(x)mp[val[x]]++;
        if(val[i]) mp[val[i]]++;
        // for(auto [a,b]:mp) cout<<a<<' '<<b<<'\n';
        if(mp.size()==1&&!mp.count(-1)) cnt[val[i]=mp.begin()->first]-=mp.begin()->second-1,ans+=(i==1);
        else if(mp.size()>0){
            if(val[i]){
                int mx=0;
                for(auto [a,b]:mp) if(a!=val[i]) mx=max(mx,b);
                if(mx>1) return cout<<"-1\n",void();
            }
            for(auto [a,b]:mp) if(~a&&b<cnt[a]) return cout<<"-1\n",void();
            ans+=max<int>(1,mp.size()-!!mp.count(-1)),val[i]=-1;
        }
        // cout<<i<<' '<<val[i]<<' '<<tot<<' '<<ans<<'\n';
    }
    cout<<ans<<'\n';
}
int main(){
    int t;cin>>t;
    for(int i=1;i<=t;i++) cout<<"Case #"<<i<<": ",solve();
}