#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;
using mint = modint998244353;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m, k;
  cin >> n >> m >> k;
  string s, t;
  cin >> s >> t;
  string u = t;
  u += '$';
  u += s;
  rep(i, n + m + 1) if ('A' <= u[i] && u[i] <= 'Z') u[i] ^= 'a' ^ 'A';
  auto z = z_algorithm(u);
  vector<mint> f1(n), f2(n), g1(m), g2(m);
  rep(i, n) ('a' <= s[i] && s[i] <= 'z' ? f1 : f2)[i] = 1;
  rep(i, m) ('a' <= t[i] && t[i] <= 'z' ? g1 : g2)[i] = 1;
  reverse(all(g1));
  reverse(all(g2));
  auto h1 = convolution(f1, g2);
  auto h2 = convolution(f2, g1);
  int ans = 0;
  rep(i, n - m + 1) {
    int diff = h1[m - 1 + i].val() + h2[m - 1 + i].val();
    ans += z[m + 1 + i] == m && 1 <= diff && diff <= k;
  }
  cout << ans << '\n';
}