#include<bits/stdc++.h>
using namespace std;

#define reg register
typedef long long ll;
#define rep(i,a,b) for(int i=a,i##end=b;i<=i##end;++i)
#define drep(i,a,b) for(int i=a,i##end=b;i>=i##end;--i)

char IO;
int rd(){
    int s=0,f=0;
    while(!isdigit(IO=getchar())) if(IO=='-') f=1;
    do s=(s<<1)+(s<<3)+(IO^'0');
    while(isdigit(IO=getchar()));
    return f?-s:s;
}

const int P=1e9+7;

const int N=1e3+10;
const int INF=1e9+10;
int b[N<<3];
int L[N],R[N];
int dp[N][N<<3];


int main(){
    rep(kase,1,rd()) {
        int n=rd(),cnt=0;
        rep(i,1,n){
            L[i]=rd();
            R[i]=rd();
            b[++cnt]=L[i],b[++cnt]=R[i];
            b[++cnt]=L[i]-1,b[++cnt]=R[i]-1;
            b[++cnt]=L[i]+1,b[++cnt]=R[i]+1;
        }
        sort(b+1,b+cnt+1),cnt=unique(b+1,b+cnt+1)-b-1;
        rep(i,1,n) rep(j,1,cnt) dp[i][j]=INF;
        rep(i,1,n) {
            L[i]=lower_bound(b+1,b+cnt+1,L[i])-b;
            R[i]=lower_bound(b+1,b+cnt+1,R[i])-b;
            if(i==1) {
                rep(i,L[1],R[1]) dp[1][i]=0;
                continue;
            }
            //cout<<L[i]<<' '<<R[i]<<endl;
            rep(j,L[i-1],R[i-1]) if(dp[i-1][j]<INF) {
                if(j<L[i]) {
                    //cout<<b[j]<<' '<<b[L[i]]<<' '<<dp[i-1][j]+(b[L[i]]-b[j]+1)/2<<endl;
                    dp[i][L[i]]=min(dp[i-1][j]+(b[L[i]]-b[j]+1)/2,dp[i][L[i]]);
                    if(L[i]<R[i]) dp[i][L[i]+1]=min(dp[i-1][j]+(b[L[i]+1]-b[j]+1)/2,dp[i][L[i]+1]);
                } else if(j>R[i]) {
                    //puts("E");
                    dp[i][R[i]]=min(dp[i][R[i]],dp[i-1][j]+(b[j]-b[R[i]]+1)/2);
                    if(L[i]<R[i]) dp[i][R[i]-1]=min(dp[i-1][j]+(b[j]-b[R[i]-1]+1)/2,dp[i][R[i]-1]);
                } else dp[i][j]=min(dp[i][j],dp[i-1][j]);
            }
            //rep(j,1,cnt) cout<<i<<' '<<b[j]<<' '<<dp[i][j]<<endl;
        }
        int ans=INF;
        rep(i,1,cnt) ans=min(ans,dp[n][i]);
        printf("%d\n",ans);
    }
}