why d wa*2?

#include <bits/stdc++.h>
#define int long long
using namespace std;
const int mod = 998244353;
int n , a[200005] , s1[200005],s2[200005],ans;
signed main()
{
    cin >> n;
    for (int i = 1 ; i <= n ; i++) {cin >>a[i]; s1[i] = (s1[i-  1] + a[i]) % mod; s2[i] = (s2[i - 1] + (int)pow(10 , (int)(log10(a[i])+1)))%mod;}
    for (int i = 1 ; i <= n ; i++)
    {
        //cout<<(s2[n] - s2[i])<<' ' <<(s1[n] - s1[i])<<endl;
        ans = (ans + a[i] * (s2[n] - s2[i])%mod + (s1[n] - s1[i])) % mod;
    }
    cout<<ans%mod;
    return 0;
}