import sys
from collections import defaultdict

MOD = 998244353

def main():
    N = int(sys.stdin.readline())
    S = sys.stdin.readline().strip()
    
    answer = 0
    dp_prev = defaultdict(int)  # (mod, has_first) -> count
    
    for i in range(N):
        current_char = S[i]
        new_dp = defaultdict(int)
        
        # Case 1: new substring [i]
        if current_char == '?':
            new_dp[(0, False)] += 1
            new_dp[(0, True)] += 3
            new_dp[(1, True)] += 3
            new_dp[(2, True)] += 3
        else:
            d = int(current_char)
            if d == 0:
                new_dp[(0, False)] += 1
            else:
                mod = d % 3
                new_dp[(mod, True)] += 1
        
        # Case 2: extend previous substrings
        for (prev_mod, prev_has_first), cnt in dp_prev.items():
            if current_char == '?':
                if not prev_has_first:
                    # Transition for ? where previous state has_first is False
                    new_dp[(0, False)] += cnt
                    new_dp[(0, True)] += 3 * cnt
                    new_dp[(1, True)] += 3 * cnt
                    new_dp[(2, True)] += 3 * cnt
                else:
                    # Transition for ? where previous state has_first is True
                    for m in [0, 1, 2]:
                        d_count = 4 if m == 0 else 3
                        new_mod = (prev_mod + m) % 3
                        new_dp[(new_mod, True)] += cnt * d_count
            else:
                d = int(current_char)
                if not prev_has_first:
                    if d == 0:
                        new_dp[(0, False)] += cnt
                    else:
                        new_mod = d % 3
                        new_dp[(new_mod, True)] += cnt
                else:
                    new_mod = (prev_mod + d) % 3
                    new_dp[(new_mod, True)] += cnt
        
        # Calculate contribution for current R
        current_contribution = 0
        current_contribution += new_dp.get((0, False), 0)
        current_contribution += new_dp.get((0, True), 0)
        answer = (answer + current_contribution) % MOD
        
        # Update dp_prev for next iteration
        dp_prev = new_dp
    
    print(answer % MOD)

if __name__ == '__main__':
    main()