During the research on properties of the greatest common divisor (GCD) of a set of numbers, Ildar, a famous mathematician, introduced a brand new concept of the weakened common divisor (WCD) of a list of pairs of integers.

For a given list of pairs of integers (a_1, b_1), (a_2, b_2), ..., (a_n, b_n) their WCD is arbitrary integer greater than 1, such that it divides at least one element in each pair. WCD may not exist for some lists.

For example, if the list looks like [(12, 15), (25, 18), (10, 24)], then their WCD can be equal to 2, 3, 5 or 6 (each of these numbers is strictly greater than 1 and divides at least one number in each pair).

You're currently pursuing your PhD degree under Ildar's mentorship, and that's why this problem was delegated to you. Your task is to calculate WCD efficiently.

Input

The first line contains a single integer n (1 ≤ n ≤ 150 000) — the number of pairs.

Each of the next n lines contains two integer values a_i, b_i (2 ≤ a_i, b_i ≤ 2 ⋅ 10^9).

Output

Print a single integer — the WCD of the set of pairs. 

If there are multiple possible answers, output any; if there is no answer, print -1.

Examples

Input

3
17 18
15 24
12 15


Output

6

Input

2
10 16
7 17


Output

-1


Input

5
90 108
45 105
75 40
165 175
33 30


Output

5

Note

In the first example the answer is 6 since it divides 18 from the first pair, 24 from the second and 12 from the third ones. Note that other valid answers will also be accepted.

In the second example there are no integers greater than 1 satisfying the conditions.

In the third example one of the possible answers is 5. Note that, for example, 15 is also allowed, but it's not necessary to maximize the output.
#include<bits/stdc++.h>
using namespace std;
#define pb(x) push_back(x)
#define mk(x, y) make_pair(x, y)
#define pln() putchar('\n')
#define cln() (cout << '\n')
#define fi first
#define se second
#define MOD 1000000007LL
typedef long long LL;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
const int MAXN = 2e5 + 10;

/*********************************************************************/
namespace fastIO {
#define BUF_SIZE 100000
#define OUT_SIZE 100000
#define ll long long
//fread->read
    bool IOerror = 0;
    inline char nc() {
        static char buf[BUF_SIZE], *p1 = buf + BUF_SIZE, *pend = buf + BUF_SIZE;
        if (p1 == pend) {
            p1 = buf; pend = buf + fread(buf, 1, BUF_SIZE, stdin);
            if (pend == p1) {IOerror = 1; return -1;}
            //{printf("IO error!\n");system("pause");for (;;);exit(0);}
        }
        return *p1++;
    }
    inline bool blank(char ch) {return ch == ' ' || ch == '\n' || ch == '\r' || ch == '\t';}
    inline void read(int &x) {
        bool sign = 0; char ch = nc(); x = 0;
        for (; blank(ch); ch = nc());
        if (IOerror)return;
        if (ch == '-')sign = 1, ch = nc();
        for (; ch >= '0' && ch <= '9'; ch = nc())x = x * 10 + ch - '0';
        if (sign)x = -x;
    }
    inline void read(ll &x) {
        bool sign = 0; char ch = nc(); x = 0;
        for (; blank(ch); ch = nc());
        if (IOerror)return;
        if (ch == '-')sign = 1, ch = nc();
        for (; ch >= '0' && ch <= '9'; ch = nc())x = x * 10 + ch - '0';
        if (sign)x = -x;
    }
    inline void read(double &x) {
        bool sign = 0; char ch = nc(); x = 0;
        for (; blank(ch); ch = nc());
        if (IOerror)return;
        if (ch == '-')sign = 1, ch = nc();
        for (; ch >= '0' && ch <= '9'; ch = nc())x = x * 10 + ch - '0';
        if (ch == '.') {
            double tmp = 1; ch = nc();
            for (; ch >= '0' && ch <= '9'; ch = nc())tmp /= 10.0, x += tmp * (ch - '0');
        }
        if (sign)x = -x;
    }
    inline void read(char *s) {
        char ch = nc();
        for (; blank(ch); ch = nc());
        if (IOerror)return;
        for (; !blank(ch) && !IOerror; ch = nc()) * s++ = ch;
        *s = 0;
    }
    inline void read(char &c) {
        for (c = nc(); blank(c); c = nc());
        if (IOerror) {c = -1; return;}
    }
//getchar->read
    inline void read1(int &x) {
        char ch; int bo = 0; x = 0;
        for (ch = getchar(); ch < '0' || ch > '9'; ch = getchar())if (ch == '-')bo = 1;
        for (; ch >= '0' && ch <= '9'; x = x * 10 + ch - '0', ch = getchar());
        if (bo)x = -x;
    }
    inline void read1(ll &x) {
        char ch; int bo = 0; x = 0;
        for (ch = getchar(); ch < '0' || ch > '9'; ch = getchar())if (ch == '-')bo = 1;
        for (; ch >= '0' && ch <= '9'; x = x * 10 + ch - '0', ch = getchar());
        if (bo)x = -x;
    }
    inline void read1(double &x) {
        char ch; int bo = 0; x = 0;
        for (ch = getchar(); ch < '0' || ch > '9'; ch = getchar())if (ch == '-')bo = 1;
        for (; ch >= '0' && ch <= '9'; x = x * 10 + ch - '0', ch = getchar());
        if (ch == '.') {
            double tmp = 1;
            for (ch = getchar(); ch >= '0' && ch <= '9'; tmp /= 10.0, x += tmp * (ch - '0'), ch = getchar());
        }
        if (bo)x = -x;
    }
    inline void read1(char *s) {
        char ch = getchar();
        for (; blank(ch); ch = getchar());
        for (; !blank(ch); ch = getchar()) * s++ = ch;
        *s = 0;
    }
    inline void read1(char &c) {for (c = getchar(); blank(c); c = getchar());}
//scanf->read
    inline void read2(int &x) {scanf("%d", &x);}
    inline void read2(ll &x) {
#ifdef _WIN32
        scanf("%I64d", &x);
#else
#ifdef __linux
        scanf("%lld", &x);
#else
        puts("error:can't recognize the system!");
#endif
#endif
    }
    inline void read2(double &x) {scanf("%lf", &x);}
    inline void read2(char *s) {scanf("%s", s);}
    inline void read2(char &c) {scanf(" %c", &c);}
    inline void readln2(char *s) {gets(s);}
//fwrite->write
    struct Ostream_fwrite {
        char *buf, *p1, *pend;
        Ostream_fwrite() {buf = new char[BUF_SIZE]; p1 = buf; pend = buf + BUF_SIZE;}
        void out(char ch) {
            if (p1 == pend) {
                fwrite(buf, 1, BUF_SIZE, stdout); p1 = buf;
            }
            *p1++ = ch;
        }
        void print(int x) {
            static char s[15], *s1; s1 = s;
            if (!x)*s1++ = '0';
            if (x < 0)out('-'), x = -x;
            while(x)*s1++ = x % 10 + '0', x /= 10;
            while(s1-- != s)out(*s1);
        }
        void println(int x) {
            static char s[15], *s1; s1 = s;
            if (!x)*s1++ = '0';
            if (x < 0)out('-'), x = -x;
            while(x)*s1++ = x % 10 + '0', x /= 10;
            while(s1-- != s)out(*s1); out('\n');
        }
        void print(ll x) {
            static char s[25], *s1; s1 = s;
            if (!x)*s1++ = '0';
            if (x < 0)out('-'), x = -x;
            while(x)*s1++ = x % 10 + '0', x /= 10;
            while(s1-- != s)out(*s1);
        }
        void println(ll x) {
            static char s[25], *s1; s1 = s;
            if (!x)*s1++ = '0';
            if (x < 0)out('-'), x = -x;
            while(x)*s1++ = x % 10 + '0', x /= 10;
            while(s1-- != s)out(*s1); out('\n');
        }
        void print(double x, int y) {
            static ll mul[] = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000,
                               1000000000, 10000000000LL, 100000000000LL, 1000000000000LL, 10000000000000LL,
                               100000000000000LL, 1000000000000000LL, 10000000000000000LL, 100000000000000000LL
                              };
            if (x < -1e-12)out('-'), x = -x; x *= mul[y];
            ll x1 = (ll)floor(x);
            if (x - floor(x) >= 0.5)++x1;
            ll x2 = x1 / mul[y], x3 = x1 - x2 * mul[y]; print(x2);
            if (y > 0) {out('.'); for (size_t i = 1; i < y && x3 * mul[i] < mul[y]; out('0'), ++i); print(x3);}
        }
        void println(double x, int y) {print(x, y); out('\n');}
        void print(char *s) {while (*s)out(*s++);}
        void println(char *s) {while (*s)out(*s++); out('\n');}
        void flush() {if (p1 != buf) {fwrite(buf, 1, p1 - buf, stdout); p1 = buf;}}
        ~Ostream_fwrite() {flush();}
    } Ostream;
    inline void print(int x) {Ostream.print(x);}
    inline void println(int x) {Ostream.println(x);}
    inline void print(char x) {Ostream.out(x);}
    inline void println(char x) {Ostream.out(x); Ostream.out('\n');}
    inline void print(ll x) {Ostream.print(x);}
    inline void println(ll x) {Ostream.println(x);}
    inline void print(double x, int y) {Ostream.print(x, y);}
    inline void println(double x, int y) {Ostream.println(x, y);}
    inline void print(char *s) {Ostream.print(s);}
    inline void println(char *s) {Ostream.println(s);}
    inline void println() {Ostream.out('\n');}
    inline void flush() {Ostream.flush();}
//puts->write
    char Out[OUT_SIZE], *o = Out;
    inline void print1(int x) {
        static char buf[15];
        char *p1 = buf;
        if (!x)*p1++ = '0';
        if (x < 0)*o++ = '-', x = -x;
        while(x)*p1++ = x % 10 + '0', x /= 10;
        while(p1-- != buf)*o++ = *p1;
    }
    inline void println1(int x) {print1(x); *o++ = '\n';}
    inline void print1(ll x) {
        static char buf[25];
        char *p1 = buf;
        if (!x)*p1++ = '0';
        if (x < 0)*o++ = '-', x = -x;
        while(x)*p1++ = x % 10 + '0', x /= 10;
        while(p1-- != buf)*o++ = *p1;
    }
    inline void println1(ll x) {print1(x); *o++ = '\n';}
    inline void print1(char c) {*o++ = c;}
    inline void println1(char c) {*o++ = c; *o++ = '\n';}
    inline void print1(char *s) {while (*s)*o++ = *s++;}
    inline void println1(char *s) {print1(s); *o++ = '\n';}
    inline void println1() {*o++ = '\n';}
    inline void flush1() {if (o != Out) {if (*(o - 1) == '\n')*--o = 0; puts(Out);}}
    struct puts_write {
        ~puts_write() {flush1();}
    } _puts;
    inline void print2(int x) {printf("%d", x);}
    inline void println2(int x) {printf("%d\n", x);}
    inline void print2(char x) {printf("%c", x);}
    inline void println2(char x) {printf("%c\n", x);}
    inline void print2(ll x) {
#ifdef _WIN32
        printf("%I64d", x);
#else
#ifdef __linux
        printf("%lld", x);
#else
        puts("error:can't recognize the system!");
#endif
#endif
    }
    inline void println2(ll x) {print2(x); printf("\n");}
    inline void println2() {printf("\n");}
#undef ll
#undef OUT_SIZE
#undef BUF_SIZE
};
/*********************************************************************/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
/**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/

//using namespace fastIO;
PLL ps[MAXN];
int n;

LL calc(LL a, LL b){
    return a*b/__gcd(a,b);
}

LL dp[MAXN][2];
int main() {
#ifndef ONLINE_JUDGE
    //freopen("x.in", "r", stdin);
#endif // ONLINE_JUDGE
    /**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
    /**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/
    /**$$$$$$$$$$$$$$$$$$$$$$$$$$$$$**/

    cin>>n;
    for(int i=1;i<=n;++i)cin>>ps[i].fi>>ps[i].se;
//    LL gd=calc(ps[1].fi,ps[1].se);
//    for(int i=2;i<=n;++i)gd=__gcd(gd,calc(ps[i].fi,ps[i].se));
//    if(gd==1)puts("-1");
//    else{
//        LL ans=0;
//
//        cout<<ans<<endl;
//    }
    dp[1][0]=ps[1].fi,dp[1][1]=ps[1].se;
    for(int i=2;i<=n;++i){
        dp[i][0]=max(__gcd(ps[i].fi,dp[i-1][0]),__gcd(ps[i].fi,dp[i-1][1]));
        dp[i][1]=max(__gcd(ps[i].se,dp[i-1][0]),__gcd(ps[i].se,dp[i-1][1]));
    }
    if(dp[n][0]==1&&dp[n][1]==1)puts("-1");
    else cout<<max(dp[n][0],dp[n][1])<<endl;
    return 0;
}
