#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i, n) for(int i=0;i<(n);++i)
#define rep1(i, n) for(int i=1;i<=(n);i++)
#define ll long long
using mint = modint998244353;
using P = pair<ll,ll>;
using lb = long double;
using T = tuple<ll, ll, ll>;
#ifdef LOCAL
#  include <debug_print.hpp>
#  define dbg(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define dbg(...) (static_cast<void>(0))
#endif

template< unsigned mod >
struct RollingHash {
  vector< unsigned > hashed, power;

  inline unsigned mul(unsigned a, unsigned b) const {
    unsigned long long x = (unsigned long long) a * b;
    unsigned xh = (unsigned) (x >> 32), xl = (unsigned) x, d, m;
    asm("divl %4; \n\t" : "=a" (d), "=d" (m) : "d" (xh), "a" (xl), "r" (mod));
    return m;
  }

  //コンストラクタ(文字列)
  RollingHash(const string &s, unsigned base = 10007) {
    int sz = (int) s.size();
    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;
    }
  }
  //[l,r)のハッシュ値を得る
  unsigned get(int l, int r) const {
    unsigned ret = hashed[r] + mod - mul(hashed[l], power[r - l]);
    if(ret >= mod) ret -= mod;
    return ret;
  }
  
  //ハッシュをつなげる
  unsigned connect(unsigned h1, int h2, int h2len) const {
    unsigned ret = mul(h1, power[h2len]) + h2;
    if(ret >= mod) ret -= mod;
    return ret;
  }

  int LCP(const RollingHash< mod > &b, int l1, int r1, int l2, int r2) {
    int len = min(r1 - l1, r2 - l2);
    int low = -1, high = len + 1;
    while(high - low > 1) {
      int mid = (low + high) / 2;
      if(get(l1, l1 + mid) == b.get(l2, l2 + mid)) low = mid;
      else high = mid;
    }
    return (low);
  }
};

using RH = RollingHash< 1000000007 >;


//segtreeに乗せる用
// long long mod = 2147483647; 

// struct S {
//     long long hash, pow;
// };

// S op(S a, S b){
//     long long na = a.hash * b.pow + b.hash;
//     na %= mod;
//     return {na, (a.pow * b.pow) % mod};
// }

// S e(){
//     return {0,1};
// }

int main()
{
    int n, m, k;
    cin >> n >> m >> k;
    string s, t;
    cin >> s >> t;
    reverse(t.begin(),t.end());
    vector<vector<ll>> a(26, vector<ll>(n)), b(26, vector<ll>(m));
    rep(i,n){
        if(isupper(s[i])) a[s[i]-'A'][i] = 1;
        else a[s[i]-'a'][i] = -1;
    }
    rep(i,m){
        if(isupper(t[i])) b[t[i]-'A'][i] = 1;
        else b[t[i]-'a'][i] = -1;
    }
    dbg(a,b);
    vector<vector<ll>> f(26);
    rep(i,26) f[i] = convolution_ll(a[i], b[i]);
    dbg(f[0]);
    reverse(t.begin(),t.end());
    rep(i,n){
        if(isupper(s[i])) s[i] = s[i]+32;
    }
    rep(i,m){
        if(isupper(t[i])) t[i]=t[i]+32;
    }
    dbg(s, t);
    RH S(s), T(t); 
    int ans = 0;
    rep(i,n){
        if(T.get(0,m)!=S.get(i,i+m)) continue;
        int c = 0;
        rep(j,26){
            if(f[j][i+m-1]<=0) c-=f[j][i+m-1];
        }
        dbg(i,c);
        if(c<=k && c>=1) ans++;
    }
    cout << ans << endl;
    return 0;
}