#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;
}