/*
	Nishant Singh
	nishant.ns19@gmail.com
*/
#include <bits/stdc++.h>
#include <functional> 
#include <iostream> 
// ******** Big Integer ********
// #include <boost/multiprecision/cpp_int.hpp>
// using namespace boost::multiprecision;
// #define ll1024  int1024_t
// ******** Big Integer ********
// ******** Using PBDS ********
// #include <ext/pb_ds/assoc_container.hpp> // Common file 
// #include <ext/pb_ds/tree_policy.hpp> 
// using namespace __gnu_pbds; 
// #define ook order_of_key    //count of strictly smaller elements
// #define fbo find_by_order   //find element at an index 
// ******** Using PBDS ********
using namespace std;
#define ll long long
#define ld long double
#define pll pair<long long,long long>
#define pii pair<int,int>
#define vll vector<ll>
#define vec vector
#define setcount(x) __builtin_popcountll(x)
#define f first
#define s second
#define mp make_pair
#define REP(i,n) for(ll i=0;i<(n);i++)
#define FOR(i,a,b) for(ll i=(a);i<=(b);i++)
#define REV(i,a,b) for(ll i=(a);i>=(b);i--)
#define pb push_back
#define in insert
#define init(x,a) memset(x,a,sizeof(x))
#define all(c) c.begin(),c.end()
#define pq priority_queue
#define ffl fflush(stdout)
#define mset multiset
#define out(x) cout<<#x<<" = "<<" "<<x<<"\n";
#define ub upper_bound
#define lb lower_bound 
#define ln "\n"
#define Y "YES"
#define N "NO"
ll const mod=1e9 + 7;
ll const inf=2e18;
// ******** Using PBDS ********
// typedef tree<long long, null_type, less<long long>, rb_tree_tag, 
//              tree_order_statistics_node_update> 
//                 os; 
// ******** Using PBDS ********
inline ll add(ll a,ll b){ 
	return (a%mod + b%mod + mod)%mod; 
}
inline ll mul(ll a,ll b){ 
	return (a%mod * b%mod + mod)%mod; 
}
inline ll sub(ll a,ll b){ 
	return (a%mod - b%mod + mod)%mod; 
}
ll gcd(ll a,ll b){
	if (b == 0) 
		return a; 
	return gcd(b, a % b);  
}
ll modexp(ll x, ll n){
	if(n==0){
		return 1;
	}
	else if(n&1){
		return (modexp((x*x)%mod, n/2)%mod * x%mod)%mod;
	}
	else{
		return (modexp((x*x)%mod, n/2)%mod);
	}
}
ll modinv(ll n){
	return modexp(n,mod-2);
}
// ******** GLOBAL VARIABLES ********
// ******** GLOBAL VARIABLES ********
ll sgn(ll x){
	if(x<0)
		return -1;
	if(x>0)
		return 1;
	return 0;
}
bool inBetwen(ll x1,ll x2,ll y){
	if(x1>x2)
		swap(x1,x2);
	return y>=x1 && y<=x2;
}
void solve(){
	ll n;
	cin>>n;
	ll t[n+1],x[n];
	REP(i,n){
		cin>>t[i]>>x[i];
	}
	t[n]=inf;
	ll xprev=0;
	ll ans=0;
	REP(i,n){
		ll dir = sgn(x[i]-xprev);
		ll j=i;
		ll endTime = t[i] + abs(x[i]-xprev);
		while(t[j]<endTime){
			ll x1=xprev+(t[j]-t[i])*dir;
			ll x2=xprev + (min(t[j+1],endTime)-t[i])*dir;
			// cout<<x1<<" "<<x2<<" "<<i<<" "<<x[i]<<ln;
			ans+=inBetwen(x1,x2,x[j]);
			j++;
		}
		if(dir==0){
			ans++;
			j=i+1;
		}
		// cout<<xprev<<" "<<i<<" "<<j<<" "<<ans<<" "<<endTime<<ln;
		xprev=x[i];
		i=j-1;
	}
	cout<<ans<<ln;
}  
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	ll T=1;
	cin>>T; 	
	for(int t=1;t<=T;t++)
	{
		// cout<<"Case #"<<t<<": ";
		solve();
	}
	return 0;
}