#include <stdio.h>
#include <string.h>

#define MOD 998244353LL

int main(void) {
    int N;
    scanf("%d", &N);
    char A[500002];
    scanf("%s", A);

    long long ans = 1;
    int zeros = 0, ones = 0;

    for (int i = 0; i < N; i++) {
        if (A[i] == '0') zeros++;
        else             ones++;

        /* end of segment: '10' boundary or last character */
        if (i == N-1 || (A[i] == '1' && A[i+1] == '0')) {
            if (zeros >= 1 && ones >= 1)
                ans = ans * (zeros + ones + 1) % MOD;
            zeros = 0;
            ones  = 0;
        }
    }

    printf("%lld\n", ans);
    return 0;
}