#include<bits/stdc++.h>

using namespace std;

#define MAXN 210

int i,n,m,tot,x;

int head[MAXN],val[MAXN],f[MAXN][MAXN],size[MAXN];

struct Edge

{

        int nxt,to;

} e[MAXN];

inline void add(int x,int y)

{

        tot++;

        e[tot] = (Edge){head[x],y};

        head[x] = tot;

}

inline void dfs(int x)

{

        int i,j,k,y;

        size[x] = ;

        for (i = head[x]; i; i = e[i].nxt)

        {

                y = e[i].to;

                dfs(y);

                size[x] += size[y];

                for (j = size[x]; j >= ; j--)

                {

                        for (k = ; k < j; k++)

                        {

                                f[x][j] = max(f[x][j],f[x][k]+f[y][j-k]);

                        }

                }

        }

}

int main() {

        while (scanf("%d%d",&n,&m) != EOF)

        {

                if (!n && !m) break;

                tot = ;

                memset(f,,sizeof(f));

                memset(size,,sizeof(size));

                for (i = ; i <= n; i++) head[i] = ;

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

                {

                        scanf("%d%d",&x,&val[i]);

                        add(x,i);

                        f[i][] = val[i];

                }

                dfs();

                printf("%d\n",f[][m+]);

        }

        return ;

}