#include<bits/stdc++.h>
using namespace std;
const int MAX_N=5+1e5;
vector<int> a,b,key;
int n;
int go(int pos,int pos1){
    int ret=abs(pos-pos1)+1>>1;
//    printf("(%d %d %d)",pos,pos1,ret);
    return ret;
}
vector<pair<int,int> > f[MAX_N];
void updata(int i,int x,int y){
    for(int j=0;j<f[i].size();++j)
        if(f[i][j].first==x){
            f[i][j].second=min(f[i][j].second,y);
            return;
        }
    f[i].push_back(make_pair(x,y));
}
int dfs(int spos){
    int ans=1e9;
    for(int i=0;i<=n;++i) f[i].clear();
    f[0].push_back(make_pair(spos,0));
    for(int i=1;i<=n;++i){
        for(vector<pair<int,int> >::iterator it=f[i-1].begin()
                ;it!=f[i-1].end();++it){
            if(it->first>=a[i]&&it->first<=b[i]){
                updata(i,it->first,it->second);
            }
            else if(it->first<a[i]){
                updata(i,a[i],it->second+go(it->first,a[i]));
                if(a[i]+1<=b[i]) 
                    updata(i,a[i]+1,it->second+go(it->first,a[i]+1));
            }else{
                updata(i,b[i],it->second+go(it->first,b[i]));
                if(b[i]-1>=a[i]) 
                    updata(i,b[i]-1,it->second+go(it->first,b[i]-1));
            }
        }
//        cerr<<f[i].size()<<endl;
    }
    for(vector<pair<int,int> >::iterator it=f[n].begin();
        it!=f[n].end();++it){
//        printf("[%d %d]",it->first,it->second);
        ans=min(ans,it->second);
    }
//    exit(0);
    return ans;
}

int main(){
    int T; scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        a.resize(n+1); b.resize(n+1); key.clear();
        for(int i=1;i<=n;++i){
            scanf("%d%d",&a[i],&b[i]);
            key.push_back(a[i]);
            key.push_back(b[i]);
        }
        sort(key.begin(),key.end());
        key.erase(unique(key.begin(),key.end()),key.end());
        int ans=1e9;
    //    printf("|%d|",dfs(20));
        for(int i=0;i<key.size();++i){
    //        printf("(%d %d)",key[i],dfs(key[i]));
            
            ans=min(ans,dfs(key[i]));
        }
        printf("%d\n",ans);
    }
    return 0;
}