#include <bits/stdc++.h>
using namespace std;
int a[100005];
long long dp[2][2][205];
const int mod = 998244353;
int M = 200;
int solve() {
  int n;
  scanf("%d", &n);
  for (int(i) = 0; (i) < (n); ++(i)) {
    scanf("%d", a + i);
  }
  for (int(j) = 1; (j) <= (M); ++(j)) {
    if (a[0] < 0 || a[0] == j) {
      dp[0][0][j] = 1;
    } else {
      dp[0][0][j] = 0;
    }
  }
  for (int(i) = 0; (i) < (2); ++(i))
    for (int(j) = 1; (j) <= (M); ++(j)) dp[0][i][j] += dp[0][i][j - 1];
  for (int i = 1; i < n; ++i) {
    int y = i & 1;
    int x = y ^ 1;
    for (int(j) = 1; (j) <= (M); ++(j)) {
      if (a[i] < 0 || a[i] == j) {
        dp[y][0][j] = dp[x][0][j - 1] + dp[x][1][j - 1];
        dp[y][1][j] =
            dp[x][0][j] - dp[x][0][j - 1] + dp[x][1][200] - dp[x][1][j - 1];
      } else {
        dp[y][0][j] = dp[y][1][j] = 0;
      }
    }
    for (int(i) = 0; (i) < (2); ++(i))
      for (int(j) = 1; (j) <= (200); ++(j))
        dp[y][i][j] = (dp[y][i][j] + dp[y][i][j - 1]) % mod;
  }
  printf("%I64d\n", (dp[(n & 1) ^ 1][1][200] + mod) % mod);
  return 0;
}
int main() { solve(); }
