#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll mod = 998244353;
const int N = 2048;
const int INF = 0x3f3f3f3f;
struct Node {
    int top, go1, push, go2;
} d[N];
int n;
char s[N], c;

bool vis[N];
int rem[N][2];
bool in[N][N];

void dfs(int x) {
    int tmp = d[x].go2, res = 1;
    rem[x][0] = -1;
    while (d[tmp].top != d[x].push) {
        if (in[x][tmp]) {
            printf("-1\n");
            exit(0);
        }
        in[x][tmp] = 1;
        if (!rem[tmp][0]) dfs(tmp);
        if (rem[tmp][0] == -1) {
            printf("-1\n");
            exit(0);
        }
        res = (res + rem[tmp][1]) % mod;
        tmp = d[rem[tmp][0]].go1;
    }
    rem[x][0] = tmp;
    rem[x][1] = res + 1;
    // printf("rem:::: %d %d %d\n",x, rem[x][0], rem[x][1]);
    return;
}

int solve() {
    int now = 1, ans = 1;
    while (d[now].go1 != -1) {
        if (vis[now]) return -1;
        vis[now] = true;
        if (!rem[now][0]) dfs(now);
        ans = (ans + rem[now][1]) % mod;
        now = d[rem[now][0]].go1;
        // printf("%d %d\n",now, ans);
    }
    return ans;
}
int main() {
    scanf("%d", &n);
    for (int i = 1; i <= n; ++i) {
        scanf(" %c", &c);
        if (c == 'P') {
            scanf("OP %d GOTO %d; PUSH %d GOTO %d", &d[i].top, &d[i].go1, &d[i].push, &d[i].go2);
        } else {
            scanf("ALT; PUSH %d GOTO %d", &d[i].push, &d[i].go2);
            d[i].go1 = -1;
            d[i].top = -1;
        }
    }
    printf("%d\n", solve());
    return 0;
}