#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))
#define Pc(x) putchar(x)
#define LB lower_bound
#define UB upper_bound
#define PB push_back
using ll=long long;using db=double;using lb=long db;using ui=unsigned;using ull=unsigned ll;
using namespace std;const int N=257+5,M=10+5,K=1e5+5,mod=1e9+7,Mod=mod-1,INF=2e9+7;const db eps=1e-5;mt19937 rnd(263082);
int n,X[N],Y[N],m,B[N*2],Bh;
ll mpow(ll x,int y,int p){ll Ans=1;while(y) y&1&&(Ans=Ans*x%p),y>>=1,x=x*x%p;return Ans;}
int GS(int p){
	int Ct=0,i;for(i=1;i<=n;i++) Ct=(Ct+1ll*X[i]*Y[i])%p;if(!Ct) return 0;
	ll Ans=1;for(i=1;Ans&&i<=m;i++) Ans=Ans*i%(p-1);return mpow(Ct,Ans,p);
}
bitset<N> f[N],g[N],Cl;
int CK(){
	int Mx=0,i,j,h;for(i=1;i<=n;i++) Mx=max(Mx,Y[i]);if(m>=514&&m-Mx>=257) return 0;
	Bh=0;for(i=1;i<=n;i++) if(Y[i]==Mx){Mx=0;}else for(j=1;j<=Y[i];j++) B[++Bh]=X[i];
	for(i=0;i<=257;i++) f[i]=Cl;f[0][0]=1;
	for(i=1;i<=Bh;i++){
		for(j=0;j<=min(Bh,m/2);j++) g[j]=f[j],f[j]=Cl;
		for(j=0;j<=min(Bh,m/2);j++){
			for(h=0;h<257;h++) if(g[j][h]) f[j][(h+B[i])%257]=1,f[j+1][(h-B[i]+257)%257]=1;
		}
	}
	for(i=1;i<=n;i++)Mx=max(Mx,Y[i]);for(i=1;i<=n;i++) if(Y[i]==Mx){
		for(j=max(0,m/2-Bh);j<=min(m/2,Y[i]);j++) if(f[m/2-j][(1ll*(Y[i]-2*j)*X[i]%257+257)%257]) return 0;
	}return 0;
}
int GA(){
	if(CK()) return 0;if(m>=12) return 1;
	int i,j;Bh=0;for(i=1;i<=n;i++) for(j=1;j<=Y[i];j++) B[++Bh]=X[i];
	ll As=1;for(i=0;i<(1<<m);i++){
		int Ct=0;for(j=0;j<m;j++) Ct+=(i>>j&1);if(Ct^(m/2)) continue;
		int Ts=0;for(j=1;j<=m;j++) Ts+=(i>>(j-1)&1?-B[j]:B[j]);As=As*(Ts%257+257)%257;
	}
	ll Fc=1;for(i=1;i<=m/2;i++) Fc=Fc*i%256;for(i=1;i<=(m+1)/2;i++) Fc=Fc*i%256;return mpow(As,Fc,257);
}
void Solve(){
	int i,j;scanf("%d",&n);m=0;for(i=1;i<=n;i++) scanf("%d%d",&X[i],&Y[i]),m+=Y[i];
	int A1=GS(3),A2=GS(5),A3=GS(17),A4=GA(); 
	for(i=0;i<65535;i++) if(i%3==A1&&i%5==A2&&i%17==A3&&i%257==A4) {printf("%d\n",i);return;}
}
int main(){
	int t;scanf("%d",&t);while(t--) Solve();
}