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

typedef long long ll;
typedef pair<int, int> pii;

#define eb emplace_back
#define all(s) (s).begin(), (s).end()
#define rep(i, a, b) for (int i = (a); i <= (b); ++i)
#define per(i, a, b) for (int i = (a); i >= (b); --i)

inline ll rd() {
    ll x = 0;
    bool f = 0;
    char c = getchar();
    for (; !isdigit(c); c = getchar()) f |= (c == '-');
    for (; isdigit(c); c = getchar()) x = x * 10 + (c ^ 48);
    return f ? -x : x;
}

constexpr int N = (1 << 20);

ll cnt[N];

void FWT(ll *a, int n, int f) {
    for (int k = 1; k < n; k <<= 1)
        for (int i = 0; i < n; i += (k << 1))
            for (int j = 0; j < k; ++j)
                if (f == 1) {
                    ll x = a[i + j];
                    ll y = a[i + j + k];
                    a[i + j] = x + y;
                    a[i + j + k] = x - y;
                } else {
                    ll x = a[i + j];
                    ll y = a[i + j + k];
                    a[i + j] = (x + y) / 2;
                    a[i + j + k] = (x - y) / 2;
                }
}

int main() {
    int n = rd(), m = rd();
    ll k = rd();
    rep(i, 1, n) {
        char s[30];
        scanf("%s", s);
        int S = 0;
        rep(j, 0, m - 1) if (s[j] == 'A') S += (1 << j);
        ++cnt[S];
    }
    FWT(cnt, 1 << m, 1);
    rep(i, 0, (1 << m) - 1) cnt[i] = cnt[i] * cnt[i];
    FWT(cnt, 1 << m, -1);
    rep(i, 0, m - 1)
        rep(s, 0, (1 << m) - 1)
            if ((s >> i) & 1) cnt[s] += cnt[s ^ (1 << i)];
    int ans = 0;
    rep(t, 0, (1 << m) - 1)
        if (1ll * n * n - cnt[(1 << m) - 1 - t] >= k) ++ans;
    printf("%d\n", ans);
    return 0;
}