#include<cstdio>
#include<algorithm>
#include<queue>
#define N_ 2010
#define pli pair<long long,int>
using namespace std;
vector<int>E[N_], F[N_], G[N_];
vector<int>L[N_], Num[N_];
int n, m, Path[N_], chk[101000];
int SP[N_], EP[N_], imp[N_], H[N_], vv[N_];
long long SD[N_], ED[N_], D[N_], DD[101000][2], INF = 1e18, U[N_];
int ord[N_];
priority_queue<pli>PQ;
struct Edge {
int a, b, c, d;
}Ed[101000];
void Push(int a, int p, long long c) {
if (D[a] <= c)return;
D[a] = c;
Path[a] = p;
PQ.push({ -c,a });
}
void Dijk(int a) {
int i;
for (i = 1; i <= n; i++)D[i] = INF, Path[i] = 0, vv[i] = 0;
Push(a, 0, 0);
while (!PQ.empty()) {
pli tp = PQ.top();
PQ.pop();
int x = tp.second;
if (vv[x])continue;
vv[x] = 1;
for (int i = 0; i < E[x].size(); i++) {
Push(E[x][i], Num[x][i], D[x] + L[x][i]);
}
}
}
int cnt;
void DFS(int a, int pp) {
int i;
if (imp[a]) {
H[a] = a;
ord[a] = cnt--;
}
else H[a] = H[pp];
for (auto &x : G[a]) {
DFS(x, a);
}
}
void Do(int st, int ed, int ck) {
int i, j;
for (i = 1; i <= n; i++) {
G[i].clear();
E[i].clear();
F[i].clear();
L[i].clear();
Num[i].clear();
}
for (i = 1; i <= m; i++) {
E[Ed[i].a].push_back(Ed[i].b);
L[Ed[i].a].push_back(Ed[i].c);
Num[Ed[i].a].push_back(i);
}
Dijk(st);
long long d = D[ed];
DD[0][ck] = d;
for (i = 1; i <= n; i++) SD[i] = D[i];
for (i = 1; i <= n; i++) {
E[i].clear();
L[i].clear();
Num[i].clear();
}
for (i = 1; i <= m; i++) {
E[Ed[i].b].push_back(Ed[i].a);
L[Ed[i].b].push_back(Ed[i].c);
Num[Ed[i].b].push_back(i);
}
Dijk(ed);
for (i = 1; i <= n; i++) {
ED[i] = D[i];
EP[i] = Path[i];
H[i] = imp[i] = 0;
}
for (i = 1; i <= n; i++) {
if(EP[i])G[Ed[EP[i]].b].push_back(i);
}
for (i = 1; i <= m; i++)chk[i] = 0;
int x = st;
imp[st] = imp[ed] = 1;
if (d < INF) {
while (x != ed) {
imp[x] = 1;
int t = EP[x];
chk[t] = 1;
x = Ed[t].b;
}
}
for (i = 1; i <= m; i++) {
if (!chk[i]) {
DD[i][ck] = SD[Ed[i].b] + ED[Ed[i].a] + Ed[i].c;
DD[i][ck] = min(DD[i][ck], d);
}
else DD[i][ck] = INF;
}
for (i = 1; i <= n; i++)U[i] = INF;
cnt = n;
DFS(ed, 0);
for (i = 1; i <= m; i++) {
if (chk[i])continue;
int a = H[Ed[i].a], b = H[Ed[i].b];
if (ord[a] < ord[b]) {
long long t = SD[Ed[i].a] + ED[Ed[i].b] + Ed[i].c;
for (j = ord[a]; j < ord[b]; j++) {
U[j] = min(U[j], t);
}
}
}
for (i = 1; i <= m; i++) {
if (!chk[i])continue;
int a = ord[Ed[i].a], b = ord[Ed[i].b];
if (a > b)swap(a, b);
DD[i][ck] = min(DD[i][ck],U[a]);
}
}
int main() {
int i, j;
scanf("%d%d", &n, &m);
for (i = 1; i <= m; i++) {
int a, b, c, d;
scanf("%d%d%d%d", &a, &b, &c, &d);
Ed[i] = { a,b,c,d };
}
Do(1, n, 0);
Do(n, 1, 1);
long long res = INF;
for (i = 0; i <= m; i++) {
res = min(res, DD[i][0] + DD[i][1] + Ed[i].d);
}
if (res > 8e17)res = -1;
printf("%lld\n", res);
}
