#include<bits/stdc++.h>
using namespace std;

const int N=111,P=998244353;

map<vector<int>,int>f[31];

int n,d;

char s[N];

int main()
{
    scanf("%s",s+1);
    n=strlen(s+1);
    scanf("%d",&d);
    vector<int> beg(n+1);
    for(int i=1;i<=n;i++)
        beg[i]=i;
    f[0][beg]++;
    for(int i=0;i<n+d;i++)
    {
        for(auto [dp,w]:f[i])
        {
            for(int j=0;j<26;j++)
            {
                vector<int> ndp(n+1);
                for(int x=0;x<=n;x++)
                {
                    ndp[x]=d+1;
                    ndp[x]=min(ndp[x],dp[x]+1);
                    if(x)
                        ndp[x]=min(ndp[x],ndp[x-1]+1);
                    if(x)
                        ndp[x]=min(ndp[x],dp[x-1]+(s[x]-'A'!=j));
                }
                f[i+1][ndp]=(f[i+1][ndp]+w)%P;
            }
        }
    }
    int ans=0;
    for(int i=0;i<=n+d;i++)
        for(auto [dp,w]:f[i])
            if(dp[n]==d)
                ans=(ans+w)%P;
    printf("%d\n",ans);
}