#include<bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

const int maxn = 2047;
const int mod = 98244353;

struct node{
	int top, go1, push, go2;
}d[maxn];
int n;
char s[maxn], c;

bool vis[maxn];
int rem[maxn][2];
int sta[maxn]; bool in[maxn];

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