#include<stdio.h>

#include<stdlib.h>

#include<string.h>

#include<algorithm>

#include<iostream>

#include<math.h>

#include<vector>

#include<queue>

using namespace std;

#define INT_MAX 0x73f3f3f

typedef struct w_w{

    int eend;

    int weight;

    int liu;

    int next;

}miao;

miao x[];

int head[];

int cnt;

int money[];

int bian[];

int dian[];

int vis[];

queue<int> q1;

int spfa(int s,int e){

    memset(bian,-,sizeof(bian));

    memset(dian,-,sizeof(dian));

    for(int i=;i<=;i++){

        money[i]=INT_MAX;

    }

    money[e]=INT_MAX;

    while(q1.size()) q1.pop();

    q1.push(s);

    money[s]=;

    while(q1.size()){

        int dang=q1.front();

        //printf("%d\n",dang);

        q1.pop();

        vis[dang]=;

        for(int i=head[dang];i!=-;i=x[i].next){

            int to=x[i].eend;

            int w=x[i].weight;

            if(x[i].liu>&&money[dang]+w<money[to]){

                money[to]=money[dang]+w;

                if(vis[to]==) q1.push(to);

                vis[to]=;

                bian[to]=i;

                dian[to]=dang;

                //printf("%d %d %d\n",dang,i,to);

                //system("pause");

            }

        }

    }

    if(money[e]!=INT_MAX) return ;

    else return ;

}

void add(int s,int e,int l,int w){

    x[cnt].eend=e;

    x[cnt].weight=w;

    x[cnt].liu=l;

    x[cnt].next=head[s];

    head[s]=cnt++;

}

int main()

{

    int m,n;

    scanf("%d %d",&m,&n);

    memset(head,-,sizeof(head));

    cnt=;

    int start=;

    int eend=;

    for(int i=;i<=m;i++){

        int a,b;

        scanf("%d %d",&a,&b);

        add(,n+i,,);

        add(n+i,,,);

        add(n+i,a,,);

        add(a,n+i,,);

        add(n+i,b,,);

        add(b,n+i,,);

    }

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

        for(int j=;j<n+;j++){

            add(i,eend,,*j+);

            add(eend,i,,-(*j+));

        }

    }

    int sum=;

    while(spfa(start,eend)){

        //printf("+++\n");

        int minn=INT_MAX;

        for(int i=eend;i!=start;i=dian[i]){

            int k=bian[i];

            //printf("+++%d\n",i);

            minn=min(minn,x[k].liu);

        }

        sum+=minn*money[eend];

        for(int i=eend;i!=start;i=dian[i]){

            int k=bian[i];

            x[k].liu-=minn;

            x[k^].liu+=minn;

            //printf("%d\n",k);

        }

    }

    printf("%d\n",sum);

    return ;

}