#include <atcoder/convolution>
#include <iostream>
#include <string>
#include <vector>
using namespace std;
using namespace atcoder;
using ll = long long;

ll conv_ch(char c) {
    ll ret;
    if (c >= 'A' && c <= 'Z') {
        ret = ((ll)(c - 'A') + 1) * 10000 + 1;
    } else {
        ret = ((ll)(c - 'a') + 1) * 10000;
    }
    return ret;
}

int main() {
    ll N, M, K;
    cin >> N >> M >> K;
    string S;
    string T;
    cin >> S;
    cin >> T;
    vector<ll> sq_sum_s(N + 1, 0);
    ll sq_sum_t = 0;
    vector<ll> val_s(N, 0);
    vector<ll> val_t(M, 0);
    for (ll i = 0; i < N; i++) {
        ll val = conv_ch(S[i]);
        sq_sum_s[i + 1] = sq_sum_s[i] + val * val;
        val_s[i] = val;
    }
    for (ll i = 0; i < M; i++) {
        ll val = conv_ch(T[M - 1 - i]);
        sq_sum_t += val * val;
        val_t[i] = val;
    }
    vector<ll> conv_st = convolution_ll(val_s, val_t);
    ll ans = 0;
    for (ll i = M - 1; i <= N - 1; i++) {
        ll diffs =
            (sq_sum_s[i + 1] - sq_sum_s[i + 1 - M]) + sq_sum_t - 2 * conv_st[i];
        if (diffs >= 1 && diffs <= K) {
            ans++;
        }
    }
    cout << ans << endl;
}