#include<bits/stdc++.h>
using namespace std;
int t,n,i,j,k,l,a[1005],b[1005],d[1005][4],f[1005][1005][4],ans;
int dis(int x,int y)
{
    if(x>y)swap(x,y);
    return y-x+1>>1;
}
int main()
{
    scanf("%d",&t);
    while(t--)
    {
        scanf("%d",&n);
        memset(f,127,sizeof(f));
        for(i=1;i<=n;i++)
        {
            scanf("%d%d",a+i,b+i);
            d[i][0]=a[i];
            d[i][1]=b[i];
            d[i][2]=min(b[i],a[i]+1);
            d[i][3]=max(a[i],b[i]-1);
            for(j=0;j<4;j++)f[0][i][j]=0;
        }
        for(i=0;i<n;i++)for(j=1;j<=n;j++)for(k=0;k<4;k++)if(f[i][j][k]!=f[0][0][0])if(d[j][k]>=a[i+1]&&d[j][k]<=b[i+1])f[i+1][j][k]=min(f[i+1][j][k],f[i][j][k]);
        else for(l=0;l<4;l++)f[i+1][i+1][l]=min(f[i+1][i+1][l],f[i][j][k]+dis(d[i+1][l],d[j][k]));
        for(ans=f[0][0][0],i=1;i<=n;i++)for(j=0;j<4;j++)ans=min(ans,f[n][i][j]);
        cout<<ans<<endl;
    }
    return 0;
}