#include <iostream>
#include <algorithm>
#include<cmath>
#include<cstring>
#include<cstdio>
#include<cstdlib>
#include<vector>
#include<iomanip>
#include<ctime>
#include<set>
#include<map>
#include<queue>
#include<stack>
#define sqr(x) ((x)*(x))
#define fz1(i,n) for ((i)=1;(i)<=(n);(i)++)
#define fd1(i,n) for ((i)=(n);(i)>=1;(i)--)
#define fz0g(i,n) for ((i)=0;(i)<=(n);(i)++)
#define fd0g(i,n) for ((i)=(n);(i)>=0;(i)--)
#define fz0k(i,n) for ((i)=0;(i)<(n);(i)++)
#define fd0k(i,n) for ((i)=(long long)((n)-1);(i)>=0;(i)--)
#define fz(i,x,y) for ((i)=(x);(i)<=(y);(i)++)
#define fd(i,y,x) for ((i)=(y);(i)>=(x);(i)--)
#define fzin fz1(i,n)
#define fzim fz1(i,m)
#define fzjn fz1(j,n)
#define fzjm fz1(j,m)
#define ff(c,itr) for (__typeof((c).begin()) itr=(c).begin();itr!=(c).end();itr++)
#define rdst(st,len){static char ss[len];scanf(" %s",ss);(st)=ss;}
#define inc(x,y) {x+=(y);if(x>=mod)x-=mod;}
#define dec(x,y) {x-=(y);if(x<0)x+=mod;}
using namespace std;
int n,m,i,j,t,l[1005],r[1005],dp[1005][6005],ans;
vector<int> all;
int main()
{
    scanf("%d",&t);
    while(t--)
    {
        all.clear();
        scanf("%d",&n);
        fz1(i,n){
            scanf("%d%d",&l[i],&r[i]);
            all.push_back(l[i]);
            all.push_back(r[i]);
            all.push_back(l[i]-1);
            all.push_back(r[i]-1);
            all.push_back(l[i]+1);
            all.push_back(r[i]+1);
        }
        sort(all.begin(),all.end());
        all.resize(unique(all.begin(),all.end())-all.begin());
        fz1(i,n){
            fz1(j,all.size()){
                dp[i][j]=0x3f3f3f3f;
            }
        }
        fz1(i,all.size()){
            dp[0][i]=0;
        }
        
        fz1(i,n){
            fz1(j,all.size())if(l[i]<=all[j-1]&&all[j-1]<=r[i]){
                dp[i][j]=dp[i-1][j];
            }
            
            int p_odd=0x3f3f3f3f,p_even=0x3f3f3f3f;
            fz1(j,all.size()){
                if(all[j-1]<l[i]){
                    if(all[j-1]&1)p_odd=min(p_odd,dp[i-1][j]-all[j-1]/2);else p_even=min(p_even,dp[i-1][j]-all[j-1]/2);
                }
                if(l[i]<=all[j-1]&&all[j-1]<=r[i]){
                    if(all[j-1]&1){
                        dp[i][j]=min(dp[i][j],p_odd+all[j-1]/2);
                        dp[i][j]=min(dp[i][j],p_even+all[j-1]/2+1);
                    }
                    else{
                        dp[i][j]=min(dp[i][j],p_odd+all[j-1]/2);
                        dp[i][j]=min(dp[i][j],p_even+all[j-1]/2);
                    }
                }
            }
            
            int s_odd=0x3f3f3f3f,s_even=0x3f3f3f3f;
            fd1(j,all.size()){
                if(r[i]<all[j-1]){
                    if(all[j-1]&1)s_odd=min(s_odd,dp[i-1][j]+all[j-1]/2);else s_even=min(s_even,dp[i-1][j]+all[j-1]/2);
                }
                if(l[i]<=all[j-1]&&all[j-1]<=r[i]){
                    if(all[j-1]&1){
                        dp[i][j]=min(dp[i][j],s_odd-all[j-1]/2);
                        dp[i][j]=min(dp[i][j],s_even-all[j-1]/2);
                    }
                    else{
                        dp[i][j]=min(dp[i][j],s_odd-all[j-1]/2+1);
                        dp[i][j]=min(dp[i][j],s_even-all[j-1]/2);
                    }
                }
            }
        }
        
        ans=0x3f3f3f3f;
        fz1(i,all.size())ans=min(ans,dp[n][i]);
        printf("%d\n",ans);
    }
    return 0;
}