#include<bits/stdc++.h>
#define int long long
#define eb emplace_back
#define mp make_pair
#define DEBUG
using namespace std;
using pii = pair<int, int>;
using piii = pair<int, pii>;
using piiii = pair<pii, pii>;
using i64 = long long;
using u64 = unsigned long long;
using u32 = unsigned int;
const int P = 998244353;const i64 inf = 0x3f3f3f3f3f3f3f3f;
namespace IO{
    #define AzusIO
    int read(int &x){
        x = 0; int ch = 1;
        char u;
        while(!(isdigit(u = getchar()))){ if(u == '-') ch = -1; }
        x = u - '0';
        while(isdigit(u = getchar())) {x = (x << 3) + (x << 1) + u - '0';}
        x *= ch; return 0;
    }
} using namespace IO;
namespace azus{
    int n;
    pii f[1105][1105];
    bool vis[1105][1105];
    int opt[1105];
    int pu[1105], po[1105], tp[1105], tp2[1105];
    pii dfs(int u, int a){
    	// cout << u << " " << a << "\n";
    	if(a == 0 && opt[u] == 0) return f[u][a] = mp(1ll, 0ll);
    	if(a == po[u]){
    		return f[u][a] = mp(1ll, tp[u]);
    	}
    	if(vis[u][a]) {
    		puts("-1");
    		exit(0); return mp(-1ll, -1ll);
    	}
    	if(f[u][a] != mp(-1ll, -1ll)) return f[u][a];
    	vis[u][a] = 1;
    	int y = tp2[u], b = pu[u];
    	auto [cnt1, z1] = dfs(y, b);
    	if(z1 == 0) f[u][a] = mp(cnt1 + 1, z1);
    	else {
    		auto [cnt2, z2] = dfs(z1, a);
    		f[u][a] = mp(cnt1 + cnt2 + 1, z2);
    	}
    	vis[u][a] = 0;
    	return f[u][a];
    }
    int main(){
    	for(int i = 0; i <= 1100; i ++)
    		for(int j = 0; j <= 1100; j ++) f[i][j] = mp(-1ll, -1ll);
        read(n);
        for(int i = 1; i <= n; i ++){
            char ch = getchar();
            if(ch == 'H'){
                opt[i] = 0;
                read(pu[i]); read(tp2[i]);
            } else {
                opt[i] = 1;
                read(po[i]); read(tp[i]); read(pu[i]); read(tp2[i]);
            }
            // cout << opt[i] << "\n";
        }
        dfs(1, 0);
        // cout << f[1][0].second << "\n";
        assert(f[1][0].second == 0);
        cout << f[1][0].first << "\n";
        return 0;
    }
}
signed main(){
#ifndef DEBUG
    // ios::sync_with_stdio(0);
    // cin.tie(0), cout.tie(0);
#endif
    int T = 1;
    while(T --)
        azus::main();
    return 0;
}