#include<cstdio>
#include<cstring>
#include<cctype>
#include<algorithm>
#include<vector>
#define pb push_back
#define mp make_pair
#define xx first
#define yy second
#define rep(i,a,b) for(int i=(a),i##_end_=(b);i<=i##_end_;i++)
#define dwn(i,a,b) for(int i=(a),i##_end_=(b);i>=i##_end_;i--)
using namespace std;
inline int read() {
    int x=0,f=1;char c=getchar();
    for(;!isdigit(c);c=getchar()) if(c=='-') f=-1;
    for(;isdigit(c);c=getchar()) x=x*10+c-'0';
    return x*f;
}
typedef long long ll;
typedef pair<int,int> pii;
const int maxn=1000010;
const int maxm=1010;
const int inf=1e9;
int l[maxm],r[maxm],tmp[maxm*6];
int n,m;
int f[2][maxm*6];
void solve() {
    n=read();m=n*2;
    rep(i,1,n) {
        tmp[i]=l[i]=read(),tmp[i+n]=r[i]=read();
        tmp[++m]=l[i]+1;tmp[++m]=r[i]-1;
        tmp[++m]=l[i]-1;tmp[++m]=r[i]+1;
    }
    sort(tmp+1,tmp+m+1);
    rep(i,1,n) {
        l[i]=lower_bound(tmp+1,tmp+m+1,l[i])-tmp;
        r[i]=lower_bound(tmp+1,tmp+m+1,r[i])-tmp;
    }
    int cur=0;
    memset(f,0,sizeof(f));
    rep(i,1,n) {
        int mnodd=inf,mneven=inf;
        cur^=1;
        rep(j,1,m) f[cur][j]=inf;
        rep(j,1,r[i]) {
            if(tmp[j]%2) mnodd=min(mnodd,f[cur^1][j]-tmp[j]/2);
            else mneven=min(mneven,f[cur^1][j]-tmp[j]/2);
            if(l[i]<=j&&j<=r[i]) {
                if(tmp[j]%2) {
                    f[cur][j]=min(f[cur][j],mnodd+tmp[j]/2);
                    f[cur][j]=min(f[cur][j],mneven+tmp[j]/2+1);
                }
                else {
                    f[cur][j]=min(f[cur][j],mnodd+tmp[j]/2);
                    f[cur][j]=min(f[cur][j],mneven+tmp[j]/2);
                }
            }
        }
        mnodd=inf,mneven=inf;
        dwn(j,m,l[i]) {
            if(tmp[j]%2) mnodd=min(mnodd,f[cur^1][j]+tmp[j]/2);
            else mneven=min(mneven,f[cur^1][j]+tmp[j]/2);
            if(l[i]<=j&&j<=r[i]) {
                if(tmp[j]%2) {
                    f[cur][j]=min(f[cur][j],mnodd-tmp[j]/2);
                    f[cur][j]=min(f[cur][j],mneven-tmp[j]/2);
                }
                else {
                    f[cur][j]=min(f[cur][j],mnodd-tmp[j]/2+1);
                    f[cur][j]=min(f[cur][j],mneven-tmp[j]/2);
                }
            }
        }
    //    rep(j,1,m) if(f[cur][j]!=inf) printf("%d %d: %d\n",i,tmp[j],f[cur][j]);
    }
    int ans=inf;
    rep(j,1,m) ans=min(ans,f[cur][j]);
    printf("%d\n",ans);
}
int main() {
    int T=read();
    while(T--) solve();
    return 0;
}