#pragma GCC optimize ("O3")

#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include <prettyprint.hpp>
#define debug(...)  cerr << "[" << #__VA_ARGS__ << "]: ", d_err(__VA_ARGS__);
#else
#define debug(...) 83;
#endif

void d_err() {
    cerr << endl;
}

template <typename H, typename... T>
void d_err(H h, T... t) {
    cerr << h << " ";
    d_err(t...);
}

template <typename T>
void print(T x) {
    cout << x << endl;
}

#define ALL(x) (x).begin(), (x).end()
#define FOR(i, m, n) for (int i = (m); i < (n); ++i)
#define REVFOR(i, m, n) for (int i = (n - 1); i >= (m); --i)
#define REP(i, n) FOR(i, 0, n)
#define REVREP(i, n) REVFOR(i, 0, n)
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define bcnt __builtin_popcountll

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef pair<ll,ll> Pll;
typedef pair<int,int> Pin;

ll INF = 1e16;
int inf = 1e9;
ll MOD = 1e9+7;

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(20);
    
    int N;
    cin >> N;

    vi X(N), Y(N); vector<char> U(N);
    REP(i, N) cin >> X[i] >> Y[i] >> U[i];

    map<ll, set<ll>> mr_down, mr_up, ml_down, ml_up;

    ll ans = inf;

    vector<pair<int, pair<int, bool>>> vr, vl;
    map<int, set<ll>> mu, md, ml, mr;
    REP(i, N) {
        if (U[i] == 'U') {
            mr_up[ Y[i] + X[i]].insert(Y[i]);
            ml_up[ Y[i] - X[i]].insert(Y[i]);
            vr.pb({X[i], {i, false}});
            vl.pb({X[i], {i, false}});

            mu[X[i]].insert(Y[i]);
            auto &tmp = md[X[i]];
            if (tmp.empty()) continue;
            auto it = tmp.lower_bound(Y[i]);
            if (it != tmp.end()) {
                ans = min(ans, (*it - Y[i]) * 10 / 2);
            }
        } else if (U[i] == 'D') {
            mr_down[ Y[i] - X[i]].insert(Y[i]);
            ml_down[ Y[i] + X[i]].insert(Y[i]);
            vr.pb({X[i], {i, false}});
            vl.pb({X[i], {i, false}});

            md[X[i]].insert(Y[i]);
            auto &tmp = mu[X[i]];
            if(tmp.empty()) continue;
            auto it = tmp.lower_bound(Y[i]);
            if (it != tmp.begin()) {
                it--;
                ans = min(ans, (Y[i] - *it) * 10 / 2);
            }
        } else if (U[i] == 'L') {
            vl.pb({X[i], {i, true}});

            ml[Y[i]].insert(X[i]);
            auto &tmp = mr[Y[i]];
            if(tmp.empty()) continue;
            auto it = tmp.lower_bound(X[i]);
            if (it != tmp.begin()) {
                it--;
                ans = min(ans, (X[i] - *it) * 10 / 2);
            }
        } else {
            vr.pb({X[i], {i, true}});

            mr[Y[i]].insert(X[i]);
            auto &tmp = ml[Y[i]];
            if(tmp.empty()) continue;
            auto it = tmp.lower_bound(X[i]);
            if (it != tmp.end()) {
                ans = min(ans, (*it - X[i]) * 10 / 2);
            }
        }
    }

    sort(ALL(vr));
    sort(ALL(vl), greater<>());

    debug(mr_down, mr_up)
    REP(i, vr.size()) {
        auto pp = vr[i];
        int id = pp.se.fi;
        bool f = pp.se.se;

        if (f) {
            debug(Y[id] - X[id])
            auto &s1 = mr_down[Y[id] - X[id]];
            if (s1.size() > 0) {
                ans = min(ans, 10 * (*s1.begin() - Y[id]));
            }

            debug( Y[id] + X[id])
            auto &s2 = mr_up[ Y[id] + X[id]];
            if (s2.size() > 0) {
                ans = min(ans, 10 * (Y[id] - *s2.rbegin()));
            }
        } else {
            mr_down[Y[id] - X[id]].erase(Y[id]);
            mr_up[Y[id] + X[id]].erase(Y[id]);
        }
    }

    debug(ml_down, ml_up)
    REP(i, vl.size()) {
        auto pp = vl[i];
        int id = pp.se.fi;
        bool f = pp.se.se;

        debug(pp)

        if (f) {
            auto &s1 = ml_down[Y[id] + X[id]];
            debug(Y[id] + X[id], s1);
            if (s1.size() > 0) {
                ans = min(ans, 10 * (*s1.begin() - Y[id]));
            }

            debug(Y[id] - X[id]);
            auto &s2 = ml_up[ Y[id] - X[id]];
            if (s2.size() > 0) {
                ans = min(ans, 10 * (Y[id] - *s2.rbegin()));
            }
        } else {
            ml_down[Y[id] + X[id]].erase(Y[id]);
            ml_up[Y[id] - X[id]].erase(Y[id]);
        }

        debug(ans)
    }

    if (ans == inf) print("SAFE");
    else print(ans);
}


Measured memory_bytes: 148856