#pragma GCC optimize("O1,O2,O3,Ofast,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pb push_back
typedef long long ll;
typedef pair<ll, ll> ii;
typedef vector<ll> vi;
const char nl = '\n';
void fastIO() {
ios::sync_with_stdio(false);
cin.tie(0);
}
ll norm(ll x, ll y) {
x %= y;
x += y;
x %= y;
return x;
}
ll intersect(pair<int, ii> s1, pair<int, ii> s2) {
// cout<<"at "<<"("<<s1.fi<<", "<<s1.se.fi<<", "<<s1.se.se<<"); ("<<s2.fi<<", "<<s2.se.fi<<", "<<s2.se.se<<")"<<endl;
// time if intersect, -1 if not
if (s1.fi > s2.fi) // ensure first is less than second
swap(s1, s2);
if (s1.fi == s2.fi) // if same direction, never intersect
return -1;
if (s1.fi == 0 && s2.fi == 1) { // x coord const, first increasing
if (s1.se.fi != s2.se.fi)
return -1;
if (norm(s1.se.se + s2.se.se) == 1 || s1.se.se > s2.se.se)
return -1;
return abs(s2.se.se - s1.se.se) / 2;
}
if (s1.fi == 2 && s2.fi == 3) { // y coord const, first increasing
if (s1.se.se != s2.se.se)
return -1;
if (norm(s1.se.fi + s2.se.fi) == 1 || s1.se.fi > s2.se.fi)
return -1;
return abs(s2.se.fi - s1.se.fi) / 2;
}
// first going N/S, other going E/W
ii ins = {s1.se.fi, s2.se.se};
// cout<<"ins: "<<ins.fi<<", "<<ins.se<<endl;
ll t1 = ins.se - s1.se.se;
if (s1.fi == 1)
t1 = -t1;
ll t2 = ins.fi - s2.se.fi;
// cout<<"t1, t2: "<<t1<<" "<<t2<<endl;
if (s2.fi == 3)
t2 = -t2;
if (t1 == t2 && t1 > 0)
return t1;
return -1;
}
int main() {
map<char, int> conv = {{'S', 0}, {'N', 1}, {'E', 2}, {'W', 3}};
fastIO();
int N;
cin>>N;
vector<pair<int, ii>> ships;
// {type, {x, y}}
map<ll, set<pair<ii, int>>> alld; // all on diagonal x+y=i, going down
// set of {{x, y}, id}
for (int i = 0; i < N; i++) {
ll x, y; char d;
cin>>x>>y>>d;
ships.pb({conv[d], {x, y}});
if (conv[d] == 0)
alld[x + y].insert({{x, y}, i});
}
/* cout<<"ships: ";
for (pair<int, ii> p : ships)
cout<<"("<<p.fi<<", "<<p.se.fi<<", "<<p.se.se<<"); ";
cout<<endl;*/
vector<pair<ll, ii>> sink;
for (int i = 0; i < N; i++) {
if (ships[i].fi == 2) { // first goes right
// cout<<"at "<<i<<endl;
ll sr = ships[i].se.fi + ships[i].se.se;
// cout<<"sr: "<<sr<<endl;
auto it = alld[sr].lower_bound({{ships[i].se.fi, -1}, -1});
if (it != alld[sr].end()) {
int j = (*it).se;
// cout<<"trying "<<j<<endl;
ll res = intersect(ships[i], ships[j]);
if (res != -1)
sink.pb({res, {i, j}});
}
}
}
sort(sink.begin(), sink.end()); // comment if TLE
/* cout<<"sinking: "<<endl;
for (pair<ll, ii> p : sink)
cout<<p.fi<<" "<<p.se.fi<<" "<<p.se.se<<endl;*/
map<ll, vector<ii>> allr;
for (pair<ll, ii> p : sink) {
allr[p.fi].pb(p.se);
}
vector<bool> alive(N, true); // still alive
for (pair<ll, vector<ii>> pr : allr) {
// cout<<"at "<<pr.fi<<endl;
set<int> toremove;
for (ii p : pr.se) {
if (alive[p.fi] && alive[p.se]) {
toremove.insert(p.fi);
toremove.insert(p.se);
}
}
for (int x : toremove) {
// cout<<"removed "<<x<<endl;
alive[x] = false;
}
}
// cout<<"ANSWER: "<<endl;
for (int i = 0; i < N; i++) {
if (alive[i])
cout<<(i + 1)<<endl;
}
}
