//determined
#include <cmath>
#include <cstdio>
#include <vector>
#include <cstring>
#include <complex>
#include <cassert>
#include <iostream>
#include <algorithm>
#define set0(x) memset(x,0,sizeof(x))
#define debug(x) cerr<<#x<<'='<<x<<endl
using namespace std;
typedef long long ll;
template<typename T> void read(T &x){
    x = 0;char ch = getchar();int f = 1;
    while(!isdigit(ch)){if(ch == '-')f*=-1;ch=getchar();};
    while(isdigit(ch)){x = x*10+ch-48;ch=getchar();}
    x*=f;
}
ll gcd(ll a,ll b){
    if(b == 0)return a;
    return gcd(b,a%b);
}
inline void ded(vector<int>& c)
{
    sort(c.begin(), c.end());
    vector<int>::iterator new_end = unique(c.begin(), c.end());
    c.erase(new_end, c.end());
}
int T,n,a[1010],b[1010],dp[2][10010];
const int inf = 1e9;
int main(){
    read(T);
    while(T--){
        read(n);
        for(int i=1;i<=n;i++){
            read(a[i]);
            read(b[i]);
        }
        vector<int> dpv;
        for(int i=1;i<=n;i++){
            dpv.push_back(a[i]-1);
            dpv.push_back(a[i]);
            dpv.push_back(a[i]+1);
            dpv.push_back(b[i]-1);
            dpv.push_back(b[i]);
            dpv.push_back(b[i]+1);
        }
        ded(dpv);
        set0(dp);
        int m = dpv.size();
        //for(auto ct:dpv) cout<<ct<<endl;
        int cu = 0;
        for(int i=1;i<=n;i++){
            int cmia[2] = {inf,inf};
            for(int j=0;j<m;j++){
                if(dpv[j]>b[i] || dpv[j]<a[i])dp[cu][j] = inf;
                dp[cu^1][j] = inf;
            }
            //cout<<"i = "<<i<<"  ";for(int j=0;j<m;j++)cout<<dpv[j]<<':'<<dp[cu][j]<<' ';
            //cout<<endl;
            if(i == n)break;
            for(int j=0;j<m;j++){
                cmia[dpv[j]%2] = min(cmia[dpv[j]%2],dp[cu][j]-dpv[j]/2);
                if(dpv[j]%2 == 0)dp[cu^1][j] = min(dp[cu^1][j],min(cmia[dpv[j]%2]+dpv[j]/2,cmia[(dpv[j]%2)^1]+dpv[j]/2));
                if(dpv[j]%2 == 1)dp[cu^1][j] = min(dp[cu^1][j],min(cmia[dpv[j]%2]+dpv[j]/2,cmia[(dpv[j]%2)^1]+dpv[j]/2+1));
            }
            cmia[0] = inf;cmia[1] = inf;
            for(int j=m-1;j>=0;j--){
                cmia[dpv[j]%2] = min(cmia[dpv[j]%2],dp[cu][j]+dpv[j]/2);
                if(dpv[j]%2 == 0)dp[cu^1][j] = min(dp[cu^1][j],min(cmia[dpv[j]%2]-dpv[j]/2,cmia[(dpv[j]%2)^1]-dpv[j]/2+1));
                if(dpv[j]%2 == 1)dp[cu^1][j] = min(dp[cu^1][j],min(cmia[dpv[j]%2]-dpv[j]/2,cmia[(dpv[j]%2)^1]-dpv[j]/2));
            }
            cu^=1;
        }
        int ans = inf;
        for(int i=0;i<m;i++)ans = min(dp[cu][i],ans);
        cout<<ans<<endl;
    }
    return 0;
}