/**************************************************************

     Problem: 1407

     User: xrdog

     Language: C++

     Result: Accepted

     Time:3056 ms

     Memory:1292 kb

 ****************************************************************/

 #include<iostream>

 #include<cstdio>

 #include<algorithm>

 #include<cstdlib>

 #include<algorithm>

 #include<vector>

 #include<cmath>

 #include<ctime>

 #include<cstring>

 #define yyj(s) freopen(s".in","r",stdin),freopen(s".out","w",stdout);

 #define llg long long

 using namespace std;

 struct node

 {

     llg c,p,l;

 }a[];

 llg i,j,k,n,m,w,x,y,aa,ans,bb,cc;

 bool f;

 void ex_gcd(const llg a,const llg b,llg &x,llg &y)

 {

     if (!b)

     {

         x=,y=;

         return ;

     }

     ex_gcd(b,a%b,x,y);

     llg temp=x;

     x=y;

     y=temp-a/b*y;

 }

 llg gcd(llg a,llg b){return b==?a:gcd(b,a%b);}

 int main()

 {

 //  yyj("savage");

     cin>>n;

     for (i=;i<=n;i++) scanf("%lld%lld%lld",&a[i].c,&a[i].p,&a[i].l);

     for (ans=;ans<=;ans++)

     {

         f=true;

         for (i=;i<n;i++)

             if (f)

             for (j=i+;j<=n;j++)

             {

                 aa=a[i].p-a[j].p; bb=ans; cc=a[j].c-a[i].c;

                 //if (!(aa>=0 && cc>=0)) continue;

                 w=gcd(aa,bb);

                 x=,y=;

                 if (cc%w) continue;

                 ex_gcd(aa/w,bb/w,x,y);

                 x=(x*(cc/w)) % (bb/w);

                 if (x<) x+=abs(bb/w);

                 if (x<=min(a[i].l,a[j].l)) {f=false; break;}

             }

         if (f)

         {

             if (ans==) ans=;

             cout<<ans;

             return ;

         }

     }

     return ;

 }