# include <bits/stdc++.h>
# define ll long long
# define fi first
# define se second
# define pii pair<int, int>
# define pll pair<ll, ll>
using namespace std;

const int sq = 317;

int par[sq + 2][100001], ukr[sq + 2][100001], idx[100001], pos[100001], val[100001];
vector< pair<pii, pii> > ss;
bool tr[100001];

int find(int a, int sz) {
	if(a == par[sz][a]) return a;
	return find(par[sz][a], sz);
}

void merge(int a, int b, int sz) {
	a = find(a, sz);
	b = find(b, sz);
	if(a == b) return;
	if(ukr[sz][a] > ukr[sz][b]) swap(a, b);
	par[sz][a] = b;
	ss.push_back({{sz, a}, {b, ukr[sz][b]}});
	ukr[sz][b] += ukr[sz][a];
	return;
}

void rollback() {
	par[ss.back().fi.fi][ss.back().fi.se] = ss.back().fi.se;
	ukr[ss.back().fi.fi][ss.back().se.fi] = ss.back().se.se;
	ss.pop_back();
}

int main() {
	int N, M;
	scanf("%d %d", &N, &M);
	
	vector< pair<pii, pii> > arr(M);
	for(int i=0;i<M;i++) {
		scanf("%d %d %d %d", &arr[i].se.fi, &arr[i].se.se, &arr[i].fi.fi, &arr[i].fi.se);
		arr[i].se.fi--;
		arr[i].se.se--;
	}
	sort(arr.begin(), arr.end());
	
	for(int i=0;i<N;i++) {
		for(int k=0;k<=sq;k++) {
			par[k][i] = par[k][i] = i;
			ukr[k][i] = 1;
		}
	}
	
	vector<pii> cpr(M);
	for(int c=0;c<M;c++) {
		cpr[c] = {arr[c].fi.se, c};
	}
	sort(cpr.begin(), cpr.end());
	for(int i=0;i<M;i++) {
		idx[cpr[i].se] = i;
		pos[i] = cpr[i].se;
		val[i] = cpr[i].fi;
	}
	
	int ans = 1e9;
	for(int i=0;i<M;i++) {
		// update status yg skrg
		tr[idx[i]] = 1;
		
		int flr = idx[i] / sq + 1;
		for(int v=flr;v<=sq + 1;v++) merge(arr[i].se.fi, arr[i].se.se, v);
		
		// skrg query
		int lf = 1, rg = sq + 1, fn = -1;
		while(lf <= rg) {
			int mid = (lf + rg) / 2;
		//	if(i == M - 1 && mid == 1) cout<<find(0, mid)<<" "<<find(N - 1, mid)<<endl;
			if(find(0, mid) == find(N - 1, mid)) {
				fn = mid;
				rg = mid - 1;
			} else lf = mid + 1;
		}
		if(fn == -1) continue;
		
	//	cout<<"mid ; "<<i<<" "<<fn<<endl;
		
		int ct = 0;
		for(int k=(fn - 1)*sq;k<fn*sq;k++) {
			if(!tr[k]) continue;
			ct++;
			merge(arr[pos[k]].se.fi, arr[pos[k]].se.se, fn - 1);
			if(find(0, fn - 1) == find(N - 1, fn - 1)) {
				ans = min(ans, arr[i].fi.fi + val[k]);
				break;
			}
		}
		while(ct--) rollback();
	}
	if(ans == 1e9) printf("-1\n");
	else printf("%d\n", ans);
	
	return 0;
}