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   给字母编码后，用NC当进制进行hash，或者直接java水过

/*
author:jxy
lang:C/C++
university:China,Xidian University
**If you need to reprint,please indicate the source**
*/
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#define INF 1E9
using namespace std;
int N,NC;
char org[1000000];
int hash[10000000];
int v[200];
int find()
{
    int i=0,j=0,now=0,hh,ans=0,len=strlen(org);
    for(i=0,j=0;i<len;i++)
    {
        if(v[org[i]]==0)v[org[i]]=++j;
        if(j==NC)break;
    }
    for(i=0;i<N;i++) now=now*NC+v[org[i]];
    ans++;hash[now]=1;
    int t=pow(NC,N-1);
    for(j=0,i=N;i<len;i++,j++)
    {
        now-=t*v[org[j]];
        now=now*NC+v[org[i]];
        if(hash[now]!=0)continue;
        hash[now]=1;ans++;
    }
    return ans;
}
int main()
{
    scanf("%d%d%s",&N,&NC,org);
    printf("%d\n",find());
    return 0;
}

import java.util.HashMap;
import java.util.Scanner;

public class Main {
	private static Scanner in;

	public static void main(String[] args) {
		HashMap<String, Boolean> vis=new HashMap<String,Boolean>();
		in = new Scanner(System.in);
		@SuppressWarnings("unused")
		int N=in.nextInt(),NC=in.nextInt();
		String s=in.next(),t;
		int i,j,len=s.length(),ans=0;
	    for(i=N,j=0;i<=len;i++,j++)
	    {

	    	t=s.substring(j, i);
	        if(vis.containsKey(t)==true) continue;
	        vis.put(t, true);
	        ans++;
	    }
	    System.out.println(ans);
	}

}

import java.util.HashMap;
import java.util.Scanner;

public class Main {
	private static Scanner in;

	public static void main(String[] args) {
		HashMap<String, Boolean> vis=new HashMap<String,Boolean>();
		in = new Scanner(System.in);
		@SuppressWarnings("unused")
		int N=in.nextInt(),NC=in.nextInt();
		String s=in.next(),t;
		int i,j,len=s.length(),ans=0;
	    for(i=N,j=0;i<=len;i++,j++)
	    {

	    	t=s.substring(j, i);
	        if(vis.containsKey(t)==true) continue;
	        vis.put(t, true);
	        ans++;
	    }
	    System.out.println(ans);
	}

}