package yukicoder;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
public class Main{
	public static void main(String[] args){
		new Main().solve();
	}
	long gcd(long t1,long t2){
		if(t1<t2){
			long d=t2;
			t2=t1;
			t1=d;
		}
		if(t2==0)return t1;
		return gcd(t2,t1%t2);
	}
	boolean hasContradiction(long[] x,long[] mod){
		int n=x.length;
		for(int i=0;i<n;i++){
			for(int j=i+1;j<n;j++){
				long g=gcd(mod[i],mod[j]);
				if((x[i]-x[j])%g!=0)return true;
			}
		}
		return false;
	}
	long MOD=1_000_000_000+7;
	void solve(){
		Prime p=new Prime();
		ArrayList<Integer> primeList=p.primeList((int)Math.sqrt(MOD));
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		long[] x=new long[n];
		long[] y=new long[n];
		HashMap<Long,long[]> map=new HashMap<Long,long[]>();
		for(int i=0;i<n;i++){
			x[i]=sc.nextLong();
			y[i]=sc.nextLong();
			ArrayList<Factor> f=p.primeFactorF(primeList, y[i]);

			for(Factor ff:f){
				if(!f.contains(ff.base))
					map.put(ff.base, new long[]{ff.exp,x[i]});
				else{
					if(map.get(ff.base)[0]<ff.exp)
						map.put(ff.base,new long[]{ff.exp,y[i]});
				}
			}
		}
		long[] X=new long[map.size()];
		long[] mod=new long[map.size()];
		int now=0;
		for(Map.Entry<Long,long[]> e:map.entrySet()){
			mod[now]=pow(e.getKey(),e.getValue()[0]);
			X[now]=e.getValue()[1]%mod[now];
			now++;
		}
		long ans=garner(X, mod);

		if(hasContradiction(x,y)){
			System.out.println(-1);
			return;
		}
		if(ans==0){
			for(int i=0;i<n;i++){
				ans=(ans*mod[i])%MOD;
			}
		}
		System.out.println(ans);
		
	}
	void tr(Object...o){System.out.println(Arrays.deepToString(o));}
	long pow(long a,long n){
		long A=a;
		long ans=1;
		while(n>=1){
			if(n%2==0){
				A=A*A;
				n/=2;
			}else if(n%2==1){
				ans=ans*A;
				n--;
			}
		}
		return ans;
	}


	long garner(long[] x,long[] m){
		int n=x.length;
		long[] gamma=new long[n];
		for(int i=0;i<n;i++){
			long prod=1;
			for(int j=0;j<i;j++){
				prod=(prod*m[j])%m[i];
			}
			gamma[i]=inv(prod,m[i]);
		}
		long[] v=new long[n];
		v[0]=x[0];
		for(int i=1;i<n;i++){
			long tmp=v[i-1];
			for(int j=i-2;j>=0;j--){
				tmp=(tmp*m[j]+v[j])%m[i];
			}
			v[i]=(x[i]-tmp)*gamma[i]%m[i];
			while(v[i]<0)v[i]+=m[i];
		}
		
		long ret=0;
		for(int i=v.length-1;i>=0;i--){
			ret=(ret*m[i]+v[i])%MOD;
		}
		return ret;
	}
	long inv(long a,long mod){
		long b = mod;
		long p = 1, q =0;
		while(b > 0){
			long c = a / b;
			long d;
			d = a;
			a = b;
			b = d % b;
			d = p;
			p = q;
			q = d - c * q;
		}
		return p<0 ? p + mod: p;
	}
	class Prime{
		boolean[] isPrimeArray(int max){
			boolean[] isPrime=new boolean[max+1];
			Arrays.fill(isPrime, true);
			isPrime[0]=isPrime[1]=false;
			for(int i=2;i*i<=max;i++){
				if(isPrime[i]){
					for(int j=2;j*i<=max;j++){
						isPrime[j*i]=false;
					}
				}
			}
			return isPrime;
		}
		 ArrayList<Integer> primeList(int max){
			 boolean[] isPrime=isPrimeArray(max);
			 ArrayList<Integer> primeList=new ArrayList<Integer>();
			 for(int i=2;i<=max;i++){
				 if(isPrime[i]){
					 primeList.add(i);
				 }
			 }
			 return primeList;
		 }
		 ArrayList<Factor> primeFactorF(ArrayList<Integer> primeList,long num){
			 ArrayList<Factor> ret=new ArrayList<Factor>();
			 for(int p:primeList){
				 int exp=0;
				 while(num%p==0){
					 num/=p;
					 exp++;
				 }
				 if(exp>0)ret.add(new Factor(p,exp));
			 }
			 if(num>1)ret.add(new Factor((int)num,1));
			 return ret;
		 }
	}
	class Factor{
		long base,exp;
		Factor(long base,long exp){
			this.base=base;
			this.exp=exp;
		}
	}
	class Pair{
		long x;
		long mod;
		Pair(long x,long mod){
			this.x=x;
			this.mod=mod;
		}
	}
}