#include<bits/stdc++.h>
#define Gc() getchar() 
#define Me(x,y) memset(x,y,sizeof(x))
#define Mc(x,y) memcpy(x,y,sizeof(x))
#define d(x,y) ((m)*(x-1)+(y))
#define R(n) (rnd()%(n)+1)
#define Pc(x) putchar(x)
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
using namespace std;using ll=long long;using db=double;using lb=long db;using ui=unsigned;using ull=unsigned long long;using pii=pair<int,int>;using LL=__int128;
const int N=2e5+5,M=N*60+5,K=600+5,mod=998244353,Mod=mod-1;const db eps=1e-9;const int INF=2e9+7;mt19937 rnd(263082);
int n,A[N],B[N],Ns[N],Nh,g[N],w[N];
void del(int Is){
	int i;
	for(i=1;i<=n;i++) if(A[i]>Is) A[i]--,B[i]--;
	for(i=Is;i<=Nh;i++) swap(w[i],w[i+1]);Nh--;
	fill(g+1,g+Nh+1,0);
	for(i=1;i<=n;i++) g[A[i]]++,g[B[i]+1]--;
	for(i=1;i<=Nh;i++) g[i]+=g[i-1];
}
void Solve(){
	int i,j;scanf("%d",&n);
	for(i=1;i<=n;i++) scanf("%d%d",&A[i],&B[i]);if(n==1){puts("1");return;}
	Nh=0;for(i=1;i<=n;i++) Ns[++Nh]=A[i],Ns[++Nh]=B[i]+1;
	sort(Ns+1,Ns+Nh+1);Nh=unique(Ns+1,Ns+Nh+1)-Ns-1;
	for(i=1;i<=n;i++) A[i]=LB(Ns+1,Ns+Nh+1,A[i])-Ns,B[i]=LB(Ns+1,Ns+Nh+1,B[i]+1)-Ns-1;
	fill(g+1,g+Nh+1,0);for(i=1;i<=n;i++) g[A[i]]++,g[B[i]+1]--;
	for(i=1;i<=Nh;i++) g[i]+=g[i-1];Nh--;for(i=1;i<=Nh;i++) w[i]=Ns[i+1]-Ns[i];
	int Is=0;for(i=1;i<=Nh;i++) if(!g[i]) {Is=i;break;}
	if(Is){
		int Ct=0;for(i=1;i<=n;i++) if(B[i]<Is) Ct++;
		if(Ct==1) del(Is);
	}
	Is=0;for(i=Nh;i;i--) if(!g[i]) {Is=i;break;}
	if(Is){
		int Ct=0;for(i=1;i<=n;i++) if(A[i]>Is) Ct++;
		if(Ct==1) del(Is);
	}
	ll ans=0;for(i=1;i<=Nh;i++) ans+=w[i];
	ans=ans*(ans-1)/2;
	if(g[1]==1) ans-=1ll*w[1]*(w[1]-1)/2;
	if(g[Nh]==1) ans-=1ll*w[Nh]*(w[Nh]-1)/2;
	if(g[1]==1&&g[Nh]==1){
		int flag=0;for(i=1;i<=n;i++) if(A[i]==1&&B[i]==Nh) flag=1;
		if(flag) ans-=1ll*w[1]*w[Nh];
	}
	printf("%lld\n",ans);
}
int main(){
	int t=1;
	scanf("%d",&t);
	while(t--) Solve();
	cerr<<clock()*1.0/CLOCKS_PER_SEC<<'\n';
}