#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
const int mod = 998244353;
//using mint = modint1000000007;
//const int mod = 1000000007;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n, m, k; cin >> n >> m >> k;
	string s, t; cin >> s >> t;
	vector<int>cnt(n);
	rep(i, 26) {
		char c = 'a' + i;
		char C = 'A' + i;
		rep(_, 2) {
			{
				vector<long long>p(s.size());
				vector<long long>q(t.size());
				rep(j, s.size()) if (s[j] == c)p[j] = 1;
				rep(j, t.size()) if (t[j] == C)q[j] = 1;
				reverse(all(q));
				auto r = convolution_ll(p, q);
				rep(j, s.size())cnt[j] += r[j + t.size() - 1];

			}
			swap(c, C);
		}
	}
	string u = t + s;
	transform(u.begin(), u.end(), u.begin(), ::tolower);
	auto z = z_algorithm(u);
	int ans = 0;
	rep(i, s.size()) {
		if (z[i + t.size()] < t.size())continue;
		if (1 <= cnt[i] && cnt[i] <= k)ans++;
	}
	cout << ans << endl;
	return 0;
}