#include <bits/stdc++.h>
#define IOS ios::sync_with_stdio(0), cin.tie(0)
#define int long long
#define endl '\n'
#define lowbit(x) (x & -x)
#define all(s) s.begin(), s.end()
#define pii pair<int,int>
#define ls(x) (x<<1)
#define rs(x) (x<<1|1)
#define here system("pause")
using namespace std;
template <class T>
inline void read(T &x){
	x = 0;
	char c = getchar();
	bool f = 0;
	for (; !isdigit(c); c = getchar()) f ^= (c == '-');
	for (; isdigit(c); c = getchar()) x = (x << 3) + (x << 1) + (c ^ 48);
	x = f ? -x : x;
}
template <class T>
inline void write(T x){
	if (x < 0) putchar('-'), x = -x;
	if (x < 10) putchar(x + 48);
	else write(x / 10), putchar(x % 10 + 48);
}
template<typename T> void chkmin(T& lhs, const T& rhs) { lhs = lhs > rhs ? rhs : lhs; }
template<typename T> void chkmax(T& lhs, const T& rhs) { lhs = lhs < rhs ? rhs : lhs; }

const int N = 2e3 + 4;
const int mod = 998244353;
const int INF = 8e18 + 9;
const double eps = 1e-9;
const double Pi = acos(-1);
inline int pow(int a, int b, int p){ int res = 1%p; while(b){ if(b&1) res=res*a%p; a=a*a%p, b>>=1;} return res;}
inline int inv(int a, int p){ return pow(a,p-2,p)%p;}
mt19937 rnd(chrono::duration_cast<chrono::nanoseconds>(chrono::system_clock::now().time_since_epoch()).count());
int randint(int L, int R) {
	uniform_int_distribution<int> dist(L, R);
	return dist(rnd);
}
struct node {
	int a, b;
	int x, y;
} Instruction[N];
int n;
pii P[N][N]; // {dis, to};
bool vis[N][N];

void dfs(int u, int t) {
	vis[u][t] = 1;
	P[u][t] = {-1, -1};
	if(t == Instruction[u].a) {
		P[u][t] = {1, Instruction[u].x};
		return;
	}

	int v = Instruction[u].y;
	int nt = Instruction[u].b;
	if(!vis[v][nt]) dfs(v, nt);

	if(P[v][nt].first == -1) {
		P[u][t] = {-1, -1};
		return;
	}

	int d = (P[v][nt].first + 1) % mod;
	v = P[v][nt].second;
	if(!vis[v][t]) dfs(v, t);

	if(P[v][t].first == -1) {
		P[u][t] = {-1, -1};
		return;
	}

	d = (d + P[v][t].first) % mod;
	P[u][t] = {d, P[v][t].second};
}

inline void sol(){
	cin >> n;
	string op;
	for(int i = 1; i <= n; i++){
		cin >> op;
		if(op == "POP") {
			// POP 1 GOTO 2; PUSH 1 GOTO 2
			cin >> Instruction[i].a >> op >> Instruction[i].x;
			cin >> op >> op;
			cin >> Instruction[i].b >> op >> Instruction[i].y;
		} else {
			// HALT; PUSH 99 GOTO 4
			Instruction[i].a = 0;
			Instruction[i].x = 0;
			cin >> op >> Instruction[i].b >> op >> Instruction[i].y;
		}
	}
	
	dfs(1, 0);
	if(!P[1][0].second) cout << P[1][0].first << endl;
	else cout << "-1\n";
}

signed main(){
	IOS;
	int tc = 1;
	// cin >> tc;
	cout << fixed << setprecision(10);
	while(tc--){
		sol();
	}
	return 0;
}