#include <bits/stdc++.h>
using namespace std;

//#define int long long
typedef long long ll;

typedef unsigned long long ul;
typedef unsigned int ui;
const ll mod = 1000000007;
// const ll mod = 998244353;
const ll INF = mod * mod;
const int INF_N = 1e+9;
typedef pair<int, int> P;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
#define all(v) (v).begin(),(v).end()
typedef pair<ll, ll> LP;
typedef long double ld;
typedef pair<ld, ld> LDP;
const ld eps = 1e-12;
const ld pi = acos(-1.0);
//typedef vector<vector<ll>> mat;
typedef vector<int> vec;

//繰り返し二乗法
ll mod_pow(ll a, ll n, ll m) {
	ll res = 1;
	while (n) {
		if (n & 1)res = res * a%m;
		a = a * a%m; n >>= 1;
	}
	return res;
}

struct modint {
	ll n;
	modint() :n(0) { ; }
	modint(ll m) :n(m) {
		if (n >= mod)n %= mod;
		else if (n < 0)n = (n%mod + mod) % mod;
	}
	operator int() { return n; }
};
bool operator==(modint a, modint b) { return a.n == b.n; }
modint operator+=(modint &a, modint b) { a.n += b.n; if (a.n >= mod)a.n -= mod; return a; }
modint operator-=(modint &a, modint b) { a.n -= b.n; if (a.n < 0)a.n += mod; return a; }
modint operator*=(modint &a, modint b) { a.n = ((ll)a.n*b.n) % mod; return a; }
modint operator+(modint a, modint b) { return a += b; }
modint operator-(modint a, modint b) { return a -= b; }
modint operator*(modint a, modint b) { return a *= b; }
modint operator^(modint a, int n) {
	if (n == 0)return modint(1);
	modint res = (a*a) ^ (n / 2);
	if (n % 2)res = res * a;
	return res;
}

//逆元(Eucledean algorithm)
ll inv(ll a, ll p) {
	return (a == 1 ? 1 : (1 - p * inv(p%a, a)) / a + p);
}
modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }

const int max_n = 1 << 18;
modint fact[max_n], factinv[max_n];
void init_f() {
	fact[0] = modint(1);
	for (int i = 0; i < max_n - 1; i++) {
		fact[i + 1] = fact[i] * modint(i + 1);
	}
	factinv[max_n - 1] = modint(1) / fact[max_n - 1];
	for (int i = max_n - 2; i >= 0; i--) {
		factinv[i] = factinv[i + 1] * modint(i + 1);
	}
}
modint comb(int a, int b) {
	if (a < 0 || b < 0 || a < b)return 0;
	return fact[a] * factinv[b] * factinv[a - b];
}
using mP = pair<modint, modint>;

int dx[4] = { 0,1,0,-1 };
int dy[4] = { 1,0,-1,0 };




void solve() {
    int n, w; cin >> n >> w;
    cout << n/w << endl;
}

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  //cout << fixed << setprecision(10);
  //init_f();
  //init();
  //int t; cin >> t; rep(i, t)solve();
  solve();
//   stop
    return 0;
}

/*
Written By mafailure
*/
//In the name of God
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp> // Common file 
#include <ext/pb_ds/tree_policy.hpp> 
#include <functional> // for less
using namespace std;
using namespace __gnu_pbds;
#define IOS ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define endl "\n"
#ifdef ill
#define int long long 
#endif
template<typename T> ostream& operator<<(ostream &os, const vector<T> &v) { os << '{'; string sep; for (const auto &x : v) os << sep << x, sep = ", "; return os << '}'; }
template<typename T, size_t size> ostream& operator<<(ostream &os, const array<T, size> &arr) { os << '{'; string sep; for (const auto &x : arr) os << sep << x, sep = ", "; return os << '}'; }
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }

void dbg_out() { cerr << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cerr << ' ' << H; dbg_out(T...); }
 
#ifdef AATIF_DEBUG
#define dbg(...) cerr << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif
//#define int long long 
// int dx[]={-1,1,0,0}; int dy[]={0,0,1,-1};
// int dx[]={2,2,-2,-2,1,1,-1,-1}; int dy[]={1,-1,1,-1,2,-2,2,-2};
const long long mod = 1e9 + 7;
const double eps=1e-9;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef pair<int, int> ii;
typedef vector< pair< int, int > > vii;
typedef map<int, int> mii;
typedef pair<int, ii> pip;
typedef pair<ii, int> ppi;
#define arrinp(arr,init,final,size,type) type* arr=new type[size];for(int i=init;i<final;i++)cin>>arr[i];
#define cr2d(arr,n,m,t) t**arr=new t*[n];for(int i=0;i<n;i++)arr[i]=new t[m];
#define w(t) int t;cin>>t; while(t--)
#define takeInp(n) int n;cin>>n;
#define fr(i,init,final) for(int i=init;i<final;i++)
#define frr(i,init,final) for(int i=init;i>=final;i--)
#define Fr(i,final) for(int i=0;i<final;i++)
#define Frr(i,first) for(int i=first;i>=0;i--)
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define all(c) (c).begin(),(c).end()
#define rall(c) (c).rbegin(),(c).rend()
#define debug(x) cerr<<">value ("<<#x<<") : "<<x<<endl;
#define setb __builtin_popcount
#define lsone(n) (n&(-n))
#define rlsone(n) (n&(n-1))
#define clr(a,b) memset(a,b,sizeof(a))
const int inf= INT_MAX;
//struct point_i{int x,y;};
struct point_i{int x,y;
point_i(){ x=0; y=0;}
point_i(int x_,int y_){x=(x_);y=(y_) ;}
};

struct point 
{
	float x,y;
	point (){x=y=0.0;}
	point (float x_,float y_){x=(x_); y=(y_);}
	bool operator < (point other) const{
	  if(fabs(x-other.x)>eps)return x<other.x;
	  return y<other.y;
		
		}
	bool operator == (point other) const {
		return fabs(other.x-x)<=eps&& fabs(other.y-y)<=eps;
		}
	
} ;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>  ordered_set; 
vi init(string s)
{
	istringstream sin(s);
	int n;
	vi arr;
	while(sin>>n)arr.push_back(n);
	return arr;
}
int power(int x, int y)
{ 
	if(y==0)return 1;
	int u=power(x,y/2);
	u=(u*u)%mod;
	if(y%2)u=(x*u)%mod;
	return u;
    
}
int gcd(int a,int b)
{
	if(a<b)return gcd(b,a);
	return (b==0?a:(a%b?gcd(b,a%b):b));
}
int gcd_e(int a,int b,int &x,int &y)
{
	
	if(b==0){x=1; y=0; return a;}
	int x1,y1;
	int p=gcd_e(b,a%b,x1,y1);
	x=y1;
	y=x1-(a/b)*y1;
	return p;
}
signed main()
{
	IOS
	int n,m; cin>>n>>m; 
	vi a(n),b(m); 
	fr(i,0,n) cin>>a[i]; 
	fr(i,0,m) cin>>b[i];
	int dp[n+1][m+1]; 
	fr(i,0,n+1)fr(j,0,m+1)dp[i][j]=inf; 
	dp[0][0]=0; 
	fr(i,0,n+1)
	{
		fr(j,0,m+1)
		{
			if(dp[i][j]==inf) continue;
			if(mp(i,j)==mp(n,m))continue;
			if(i!=n)dp[i+1][j]=min(dp[i+1][j],dp[i][j]+1);
			if(j!=m)dp[i][j+1]=min(dp[i][j+1],dp[i][j]+1);
			if(i!=n&&j!=m)dp[i+1][j+1]=min(dp[i+1][j+1],dp[i][j]+2),
			dp[i+1][j+1]=min(dp[i+1][j+1],dp[i][j]+(a[i]!=b[j]));
		}
	}
	cout<<dp[n][m]<<endl;
	
}

