#include <cstdio>
#include <cmath>
#include <cstring>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <set>
#include <vector>
#include <sstream>
#include <queue>
#include <typeinfo>
#include <fstream>
typedef long long ll;
using namespace std;
//freopen("D.in","r",stdin);
//freopen("D.out","w",stdout);
#define sspeed ios_base::sync_with_stdio(0);cin.tie(0)
#define maxn 101
const int inf=0x7fffffff;   //无限大

int m,n;
int price[maxn][maxn];
int lv[maxn];
int x[maxn];
int dist[maxn];

int visit[maxn];

void init()
{
    memset(price,0,sizeof(price));
    memset(lv,0,sizeof(lv));
    memset(dist,inf,sizeof(dist));
    memset(visit,0,sizeof(visit));

    cin>>m>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>price[0][i]>>lv[i]>>x[i];
        for(int j=1;j<=x[i];j++)
        {
            int t,u;
            cin>>t>>u;
            price[t][i]=u;
        }
    }
}

int dijkstra()
{
    int node;
    int sd;
    int i,j;
    for(i=1;i<=n;i++)
        dist[i]=price[0][i];

    for(i=1;i<=n;i++)
    {
        node=0;
        sd=inf;
        for(j=1;j<=n;j++)
        {
            if(!visit[j]&&sd>dist[j])
            {
                sd=dist[j];
                node=j;
            }
        }
        if(node==0)
            break;

        visit[node]=1;
        for(j=1;j<=n;j++)
        {
            if(!visit[j]&&price[node][j]>0 && dist[j]>dist[node]+price[node][j])
                dist[j]=dist[node]+price[node][j];
        }
    }
    return dist[1];
}

int main()
{
    init();
    int temp_price;
    int maxlv;
    int minprice=inf;

    for(int i=1;i<=n;i++)
    {
        maxlv=lv[i];
        for(int j=1;j<=n;j++)
        {
            if(lv[j]>maxlv||maxlv-lv[j]>m)
                visit[j]=1;
            else
                visit[j]=0;
        }
        temp_price=dijkstra();
        if(minprice>temp_price)
            minprice=temp_price;
    }
    cout<<minprice<<endl;
    return 0;
}