#include<bits/stdc++.h>
using namespace std;
long long int dp[100005][2];
long long int mod=1e9+7;
int main() {
    int t;
    cin>>t;
    while(t--){
        int n,k;
        cin>>n>>k;
        char c[30];
        for(int i=0;i<k;i++)
            cin>>c[i];
        dp[0][0]=k;
        for(int i=1;i<n;i++) {
            if( i % 2 == 0){
                dp[i][0] = ( ( dp[i-1][0] * ( k - 1) ) % mod +  ( dp[i-1][1] * k) % mod) % mod;
            }
            else {
                dp[i][0] = (dp[i-1][0] * (k-1)) % mod;
                dp[i][1] = (dp[i-1][0] * (26-k)) % mod;
            }
        }
        cout << (dp[n-1][0] + dp[n-1][1])%mod << endl;
    }
}