#include<iostream>

#include<cstdlib>

#include<cstdio>

#include<cmath>

#include<cstring>

#include<algorithm>

#include<iomanip>

#include<ctime>

#include<queue>

#include<stack>

#define rg register

#define lst long long

#define N 1050

using namespace std;

int m,n,use,fir=,need;

int fy[N];

bool b[N];

inline int read()

{

    rg int s=,m=;rg char ch=getchar();

    while(ch!='-'&&(ch<''||ch>''))ch=getchar();

    if(ch=='-')m=-,ch=getchar();

    while(ch>=''&&ch<='')s=(s<<)+(s<<)+ch-'',ch=getchar();

    return s*m;

}

int main()

{

    m=read(),n=read();

    for(rg int i=;i<=n;++i)

    {

        rg int x=read();

        if(!b[x])

        {

            if(use==m+fir-)

            {

                b[fy[fir++]]=;

            }

            need++;

            fy[++use]=x;b[x]=;

        }

    }

    cout<<need<<endl;

    return ;

}