using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.IO;
using System.Reflection;
using static System.Math;
using System.Numerics;
using nint=System.Int32;
static class Program{
	const int mod=(int)1e9+7;
	const double eps=1e-11;
	static void Main(){
		Sc sc=new Sc();
		var n=sc.I;
		var a=new int[n][];
		for(int i = 0;i<n;i++) {
			var e=sc.Sa;
			int c=e[2][0];
			a[i]=new int[]{int.Parse(e[0]),int.Parse(e[1]),c};
		}
		a=a.OrderBy(x=>x[0]).ThenBy(x=>x[1]).ToArray();
		var da=Enumerable.Repeat(mod,500000).ToArray();
		var ua=Enumerable.Repeat(mod,500000).ToArray();
		var la=Enumerable.Repeat(mod,200010).ToArray();
		var lda=Enumerable.Repeat(mod,500000).ToArray();
		var lua=Enumerable.Repeat(mod,500000).ToArray();
		int ans=mod;
		for(int i = n-1;i>=0;i--) {
			if(a[i][2]=='D'){
				da[200000+a[i][0]-a[i][1]]=a[i][0];
				ans=Min(ans,(lda[400010-a[i][0]-a[i][1]]-a[i][0])*10);
			}
			else if(a[i][2]=='U'){
				if(i!=n-1&&a[i+1][2]=='D'&&a[i][0]==a[i+1][0]){ans=Min(ans,Abs(a[i+1][1]-a[i][1])*5);}
				ua[400010-a[i][0]-a[i][1]]=a[i][0];
				ans=Min(ans,(lua[200000+a[i][0]-a[i][1]]-a[i][0])*10);
			}
			else if(a[i][2]=='R'){
				ans=Min(ans,(da[200000+a[i][0]-a[i][1]]-a[i][0])*10);
				ans=Min(ans,(ua[400010-a[i][0]-a[i][1]]-a[i][0])*10);
				if(la[a[i][1]]!=mod){ans=Min(ans,Abs(la[a[i][1]]-a[i][0])*5);}
			}
			else{
				la[a[i][1]]=a[i][0];
				lua[200000+a[i][0]-a[i][1]]=a[i][0];
				lda[400010-a[i][0]-a[i][1]]=a[i][0];
			}
		}
		Console.WriteLine("{0}",ans<2000010?ans.ToString():"SAFE");
	}
}
public class Sc{
	public int I{get{return int.Parse(Console.ReadLine());}}
	public long L{get{return long.Parse(Console.ReadLine());}}
	public double D{get{return double.Parse(Console.ReadLine());}}
	public string S{get{return Console.ReadLine();}}
	public int[] Ia{get{return Array.ConvertAll(Console.ReadLine().Split(),int.Parse);}}
	public long[] La{get{return Array.ConvertAll(Console.ReadLine().Split(),long.Parse);}}
	public double[] Da{get{return Array.ConvertAll(Console.ReadLine().Split(),double.Parse);}}
	public string[] Sa{get{return Console.ReadLine().Split();}}
	public object[] Oa{get{return Console.ReadLine().Split();}}
	public int[] Ia2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),int.Parse);}}
	public int[] Ia3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),int.Parse);}
	public int[] Ia3(int a){return Array.ConvertAll((Console.ReadLine()+" "+a.ToString()).Split(),int.Parse);}
	public long[] La2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),long.Parse);}}
	public long[] La3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),long.Parse);}
	public long[] La3(int a){return Array.ConvertAll((Console.ReadLine()+" "+a.ToString()).Split(),long.Parse);}
	public double[] Da2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),double.Parse);}}
	public double[] Da3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),double.Parse);}
	public T[] Arr<T>(int n,Func<T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f();}return a;}
	public T[] Arr<T>(int n,Func<int,T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i);}return a;}
	public T[] Arr<T>(int n,Func<string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(Console.ReadLine().Split());}return a;}
	public T[] Arr<T>(int n,Func<int,string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i,Console.ReadLine().Split());}return a;}
}

Measured memory_bytes: 62356