#include <bits/stdc++.h>
using namespace std;
const int M = 998244353;
int N;
int arr[100000];
int memo[100000][201][2];
int main() {
  scanf("%d", &N);
  for (int i = 0; i < N; ++i) scanf("%d", &arr[i]);
  for (int idx = N - 1; idx >= 0; --idx) {
    for (int n = 1; n <= 200; ++n) {
      for (int t = 0; t <= 1; ++t) {
        int& ret = memo[idx][n][t];
        if (arr[idx] != -1 && arr[idx] != n)
          ret = 0;
        else if (idx == N - 1)
          ret = t;
        else {
          ret = ((memo[idx + 1][n][1] + memo[idx + 1][200][0]) % M -
                 memo[idx + 1][n][0] + M) %
                M;
          if (t == 0) ret = (ret - memo[idx + 1][n - 1][1] + M) % M;
        }
      }
    }
    for (int t = 0; t <= 1; ++t) {
      for (int n = 1; n <= 200; ++n)
        memo[idx][n][t] = (memo[idx][n][t] + memo[idx][n - 1][t]) % M;
    }
  }
  printf("%d\n", memo[0][200][0]);
}
