#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int S=26;
const int maxn=2e5+5;
int cnt[S];
bool dp[maxn];
char St[maxn];
int main()
{
int t;
cin >> t;
while (t--)
{
int n,m,s;
cin >> n >> m >> s;
memset(cnt,0,sizeof(cnt));
cin >> St;
long long ans=1e18+5;
for (int i=0;i<s;i++)
cnt[St[i]-'A']++;
for (int i=0;i<26;i++)
{
if (cnt[i]==0) continue;
memset(dp,false,sizeof(dp));
dp[0]=true;
for (int j=0;j<26;j++)
{
if (i==j) continue;
if (cnt[j]!=0)
for (int k=n-cnt[j];k>=0;k--)
if (dp[k])
dp[k+cnt[j]]=1;
}
for (int k=max(n-cnt[i],0);k<=n;k++)
if (dp[k])
ans=min(ans,1ll*(n-k)*max(0,m-(s-k-cnt[i])));
}
cout << ans << endl;
}
}/*2
2 7 9
EEZZEEZZZ*/