//#include <bits/stdc++.h>
#include "bits/stdc++.h"
using namespace std;
typedef long long ll;

#include "boost/multiprecision/cpp_int.hpp"
#include "boost/multiprecision/cpp_dec_float.hpp"
namespace mp = boost::multiprecision;
typedef mp::cpp_int LL;
typedef mp::number<mp::cpp_dec_float<1024>> DD;// 仮数部が1024ビットの浮動小数点数型(TLEしたら小さくする)

 
typedef long double dd;
#define i_7 (ll)(1E9+7)
//#define i_7 998244353
#define i_5 i_7-2
ll mod(ll a){
    ll c=a%i_7;
    if(c>=0)return c;
    return c+i_7;
}
typedef pair<ll,ll> l_l;
typedef pair<dd,dd> d_d;
ll inf=(ll)1E16;
#define rep(i,l,r) for(ll i=l;i<=r;i++)
#define rrep(i,r,l) for(ll i=r;i>=l;i--)
#define pb push_back
ll max(ll a,ll b){if(a<b)return b;else return a;}
ll min(ll a,ll b){if(a>b)return b;else return a;}
void Max(ll &pos,ll val){pos=max(pos,val);}//Max(dp[n],dp[n-1]);
void Min(ll &pos,ll val){pos=min(pos,val);}
void Add(ll &pos,ll val){pos=mod(pos+val);}
dd EPS=1E-9;
#define fastio ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define fi first
#define se second
#define endl "\n"  //インタラクティブで消す！！！！！！！！！！！！！！！！！！！！！
#define SORT(v) sort(v.begin(),v.end())
#define ERASE(v) v.erase(unique(v.begin(),v.end()),v.end())
#define POSL(v,x) (lower_bound(v.begin(),v.end(),x)-v.begin())
#define POSU(v,x) (upper_bound(v.begin(),v.end(),x)-v.begin())
template<class T,class S>
inline bool chmax(T &a, S b) {
    if(a < b) {
        a = b;
        return true;
    }
    return false;
}
template<class T,class S>
inline bool chmin(T &a, S b) {
    if(a > b) {
        a = b;
        return true;
    }
    return false;
}

void mod_print(ll k){
    ll P=50000;
    rep(y,1,P){
        ll x=mod(y*k);
        
        if(abs(x)<=P||x+P>=i_7){
            if(x+P>=i_7){
                x-=i_7;
            }
            cout<<x<<"/"<<y<<endl;
            //cout<<setprecision(5)<<(dd)x/(dd)y;
            return;
        }
    }
    cout<<"nun"<<endl;
}
#define all(c) c.begin(),c.end()
typedef vector<ll> vl;
//////////////////////////

ll ans=inf;


void cal(vector<l_l>a,vector<l_l>b){
    if(a.size()==0||b.size()==0)return;
    ll N=400005;
    //ll N=4000;
    vector<ll>v[N];
    for(auto x:b){
        v[x.fi+x.se].pb(x.fi);
    }
    
    rep(i,0,N-1)SORT(v[i]);
    
    for(auto p:a){
        ll sum=p.fi+p.se;
        if(v[sum].size()==0)continue;
        ll pos=POSU(v[sum],p.fi);
        pos--;
        if(pos>=0){
            chmin(ans,10*(p.fi-v[sum][pos]));
        }
    }
}
void che(vector<ll>a,vector<ll>b){
    vector<l_l>v;
    for(auto x:a)v.pb({x,1});
    for(auto x:b)v.pb({x,2});
    SORT(v);
    ll vs=v.size();
    rep(i,0,vs-2){
        if(v[i].se==1&&v[i+1].se==2){
            chmin(ans,5*(v[i+1].fi-v[i].fi));
        }
    }
}

int main(){fastio
    string SS="URDL";
    vector<l_l>v[4];
    ll n;cin>>n;
    rep(i,0,n-1){
        ll x,y;string s;cin>>x>>y>>s;
        rep(j,0,3){
            if(SS[j]==s[0]){
                v[j].pb({x,y});
            }
        }
    }
    rep(i,0,3){
        if(i%2==0){
            SORT(v[i]);
        }else{
            sort(v[i].begin(),v[i].end(),[](l_l xx,l_l yy){
                return xx.se<yy.se;
            });
        }
    }
    ll p0=0,p2=0;
    ll vs[4];rep(i,0,3)vs[i]=v[i].size();
    rep(x,0,200000){
        vector<ll>a,b;
        while(p0<vs[0]&&v[0][p0].fi==x){
            a.pb(v[0][p0].se);
            p0++;
        }
        while(p2<vs[2]&&v[2][p2].fi==x){
            b.pb(v[2][p2].se);
            p2++;
        }
        if(a.size()>=1&&b.size()>=1){
            che(a,b);
        }
    }
    ll p1=0,p3=0;
    rep(y,0,200000){
        vector<ll>a,b;
        while(p1<vs[1]&&v[1][p1].se==y){
            a.pb(v[1][p1].fi);
            p1++;
        }
        while(p3<vs[3]&&v[3][p3].se==y){
            b.pb(v[3][p3].fi);
            p3++;
        }
        if(a.size()>=1&&b.size()>=1){
            che(a,b);
        }
    }
    
 //   cerr<<ans<<endl;
    
    ll N=200000;
   // ll N=2000;
    vector<l_l>a,b;
    for(auto x:v[0])a.pb(x);
    for(auto x:v[1])b.pb(x);
    cal(a,b);
    a.clear();b.clear();
    
    for(auto x:v[2])a.pb({x.fi,N-x.se});
    for(auto x:v[1])b.pb({x.fi,N-x.se});
    cal(a,b);
    a.clear();b.clear();
    for(auto x:v[0])a.pb({N-x.fi,x.se});
    for(auto x:v[3])b.pb({N-x.fi,x.se});
    cal(a,b);
    a.clear();b.clear();
    for(auto x:v[2])a.pb({N-x.fi,N-x.se});
    for(auto x:v[3])b.pb({N-x.fi,N-x.se});
    cal(a,b);
    
    if(ans==inf)cout<<"SAFE"<<endl;
    else cout<<ans<<endl;
    return 0;
}


Measured memory_bytes: 23672