#include <iostream>

#include <cstring>

#include <queue>

using namespace std;

int m,n;

struct adjlist{

    int c[101],t[101];

}a[101];

int d[101],tm[101],l[101],r[101];

queue<int >que;

int abs(int x){

    return x>0?x:-x;

}

int spfa(int ls,int ll){

    que.push(1);

    int f,t;

    r[1]=0;

    while(!que.empty()){

        f=que.front();

        que.pop();

        for(int i=0;i<tm[f];i++){

            t=a[f].t[i];

            if(l[t]<=ll&&l[t]>=ls&&r[t]>r[f]+a[f].c[i]){

                r[t]=r[f]+a[f].c[i];

                que.push(t);

            }

        }

    }

    int minn=1000000;

    for(int i=1;i<=n;i++){

        minn=min(minn,r[i]+d[i]);

    }

    return minn;

}

int main(){

    ios::sync_with_stdio(false);

    int temp;

    cin>>m>>n;

    for(int i=1;i<=n;i++){

        cin>>d[i]>>l[i]>>tm[i];

        temp=tm[i];

        for(int j=0;j<temp;j++){

            cin>>a[i].t[j]>>a[i].c[j];

        }

    }

    int ans=10000;

    for(int i=l[1]-m;i<=l[1];i++){

        for(int j=1;j<=n;j++)r[j]=100000;

        ans=min(ans,spfa(i,i+m));

    }

    cout<<ans<<endl;

    return 0;

}