#include "bits/stdc++.h"
#include <random>
#include <chrono>
#define ALL(x) (x).begin(), (x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define SZ(x) ((lint)(x).size())
#define FOR(i, begin, end) for(lint i=(begin),i##_end_=(end);i<i##_end_;++i)
#define IFOR(i, begin, end) for(lint i=(end)-1,i##_begin_=(begin);i>=i##_begin_;--i)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
#define endk '\n'
using namespace std; typedef unsigned long long _ulong; typedef long long lint; typedef long double ld; typedef pair<lint, lint> plint; typedef pair<ld, ld> pld;
struct fast_ios { fast_ios() { cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(30); }; } fast_ios_;
template<class T> auto add = [](T a, T b) -> T { return a + b; };
template<class T> auto mul = [](T a, T b) -> T { return a * b; };
template<class T> auto f_max = [](T a, T b) -> T { return max(a, b); };
template<class T> auto f_min = [](T a, T b) -> T { return min(a, b); };
template<class T> using V = vector<T>;
using Vl = V<lint>; using VVl = V<Vl>; using VVVl = V<V<Vl>>;
template< typename T > ostream& operator<<(ostream& os, const vector< T >& v) {
    for (int i = 0; i < (int)v.size(); i++) os << v[i] << (i + 1 != v.size() ? " " : "");
    return os;
}
template< typename T >istream& operator>>(istream& is, vector< T >& v) {
    for (T& in : v) is >> in;
    return is;
}
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
template <class T>
T div_floor(T a, T b) {
    if (b < 0) a *= -1, b *= -1;
    return a >= 0 ? a / b : (a + 1) / b - 1;
}
template <class T>
T div_ceil(T a, T b) {
    if (b < 0) a *= -1, b *= -1;
    return a > 0 ? (a - 1) / b + 1 : a / b;
}
template <class F> struct rec {
    F f;
    rec(F&& f_) : f(std::forward<F>(f_)) {}
    template <class... Args> auto operator()(Args &&... args) const {
        return f(*this, std::forward<Args>(args)...);
    }
};
lint gcd(lint a, lint b) { if (b == 0) return a; else return gcd(b, a % b); }
lint digit(lint a) { return (lint)log10(a); }
lint e_dist(plint a, plint b) { return abs(a.first - b.first) * abs(a.first - b.first) + abs(a.second - b.second) * abs(a.second - b.second); }
lint m_dist(plint a, plint b) { return abs(a.first - b.first) + abs(a.second - b.second); }
bool check_overflow(lint a, lint b, lint limit) { if (b == 0) return false; return a > limit / b; } // a * b > c => true
void Worshall_Floyd(VVl& g) { REP(k, SZ(g)) REP(i, SZ(g)) REP(j, SZ(g)) chmin(g[i][j], g[i][k] + g[k][j]); }
const lint MOD1000000007 = 1000000007, MOD998244353 = 998244353, INF = 2e18;
lint dx[8] = { 0, 1, 0, -1, 1, -1, 1, -1 }, dy[8] = { 1, 0, -1, 0, -1, -1, 1, 1 };
bool YN(bool flag) { cout << (flag ? "YES" : "NO") << endk; return flag; } bool yn(bool flag) { cout << (flag ? "Yes" : "No") << endk; return flag; }
struct Edge {
    lint from, to;
    lint cost;
    Edge() {

    }
    Edge(lint u, lint v, lint c) {
        cost = c;
        from = u;
        to = v;
    }
    bool operator<(const Edge& e) const {
        return cost < e.cost;
    }
};
struct WeightedEdge {
    lint to;
    lint cost;
    WeightedEdge(lint v, lint c) {
        to = v;
        cost = c;
    }
    bool operator<(const WeightedEdge& e) const {
        return cost < e.cost;
    }
};
using WeightedGraph = V<V<WeightedEdge>>;
typedef pair<lint, plint> tlint;
typedef pair<ld, ld> pld;
typedef pair<plint, plint> qlint;
typedef pair<Edge, lint> pEd;
typedef pair<plint, V<plint>> vVl;
typedef pair<string, string> pstr;
typedef pair<ld, lint> pint;
typedef pair<lint, set<pint>> pset;

struct RollingHash {
	const _ulong MASK30 = (1ULL << 30) - 1;
	const _ulong MASK31 = (1ULL << 31) - 1;
	const _ulong MOD = (1ULL << 61) - 1;
	const _ulong MASK61 = MOD;

	vector<_ulong> hashed, power;

	RollingHash(const string& s, _ulong base) {
		int sz = SZ(s);
		hashed.assign(sz + 1, 0);
		power.assign(sz + 1, 0);
		power[0] = 1;
		for (int i = 0; i < sz; i++) {
			power[i + 1] = mul(power[i], base);
			hashed[i + 1] = mul(hashed[i], base) + s[i];
			if (hashed[i + 1] >= MOD) hashed[i + 1] -= MOD;
		}
	}

	//乱数生成、main関数にコピペする
	void generate_base() {
		_ulong base;
		{
			//乱数生成
			random_device seed_gen;
			mt19937 engine(seed_gen());
			uniform_real_distribution<> dist1(129, INT_MAX);
			base = dist1(engine);
		}
	}

	_ulong get(int l, int r) const {
		_ulong ret = hashed[r] + MOD - mul(hashed[l], power[r - l]);
		if (ret >= MOD) ret -= MOD;
		return ret;
	}

	//a*b mod 2^61-1を返す関数
	inline _ulong mul(_ulong a, _ulong b) const {
		_ulong u_a = a >> 31;//aの31bit以降
		_ulong d_a = a & MASK31;//aの31bit未満
		_ulong u_b = b >> 31;
		_ulong d_b = b & MASK31;

		_ulong mid = d_a * u_b + u_a * d_b;
		_ulong u_mid = mid >> 30;
		_ulong d_mid = mid & MASK30;
		return CalcMod(u_a * u_b * 2 + u_mid + (d_mid << 31) + d_a * d_b);
	}

	//mod 2^61-1を返す関数
	inline _ulong CalcMod(_ulong x) const {
		_ulong u_x = x >> 61;
		_ulong d_x = x & MASK61;
		_ulong res = u_x + d_x;
		if (res >= MOD) res -= MOD;
		return res;
	}
};

#include<atcoder/all>
using namespace atcoder;

using mint = modint998244353;

void solve() {
	lint N, M, K;
	cin >> N >> M >> K;
	string s, t;
	cin >> s >> t;
	reverse(ALL(t));
	plint p = { 'a', 'A' };
    lint ans = 0;
    Vl sum(N - M + 1);
    REP(k, 26) {
		REP(_, 2) {
			V<mint> arr(N), _arr(M);
			REP(i, N) if (s[i] - p.first == k) arr[i] = 1;
			REP(i, M) if (t[i] - p.second == k) _arr[i] = 1;
			
            auto v = convolution(arr, _arr);
            REP(i, N - M + 1) {
                sum[i] += v[i + M - 1].val();
            }
            swap(p.first, p.second);
		}
	}

	_ulong base;
	{
		//乱数生成
		random_device seed_gen;
		mt19937 engine(seed_gen());
		uniform_real_distribution<> dist1(129, INT_MAX);
		base = dist1(engine);
	}

	REP(i, N) if ('A' <= s[i] && s[i] <= 'Z') s[i] -= 'A', s[i] += 'a';
	REP(i, M) if ('A' <= t[i] && t[i] <= 'Z') t[i] -= 'A', t[i] += 'a';
	reverse(ALL(t));
	RollingHash rh1(s, base), rh2(t, base);

	REP(i, N - M + 1) {
		if (1 <= sum[i] && sum[i] <= K && rh1.get(i, i + M) == rh2.get(0, M)) ans++;
	}
    cout << ans << endk;
}

int main() {
    lint T = 1;
    //cin >> T;
    while (T--) solve();
}