#include <cstdio>#include <cstring>#include <cmath>#include <algorithm>#include <climits>#include <string>#include <iostream>#include <map>#include <cstdlib>#include <list>#include <set>#include <queue>#include <stack>using namespace std;typedef long long LL;const int maxn = 205;const int maxm = maxn * maxn;const int INF = INT_MAX / 3;int cap[maxn][maxn],flow[maxn][maxn],low[maxm];int q[maxn],alpha[maxn],pre[maxn];int uu[maxm],vv[maxm];int n,m,s,t,qs,qe;void solve() {    memset(flow,0,sizeof(flow));    while(1) {        qs = qe = 0;        for(int i = s;i <= t;i++) pre[i] = -2;        pre[s] = -1; alpha[s] = INF;        q[qe++] = s;        while(qs < qe) {            int now = q[qs++];            for(int i = s;i <= t;i++) {                if(cap[now][i] - flow[now][i] != 0 && pre[i] == -2) {                    q[qe++] = i;                    pre[i] = now;                     alpha[i] = min(alpha[now],cap[now][i] - flow[now][i]);                }            }        }        if(pre[t] == -2) break;        for(int i = t;pre[i] != -1;i = pre[i]) {            flow[pre[i]][i] += alpha[t];            flow[i][pre[i]] -= alpha[t];        }    }    bool ok = true;    for(int i = s + 1;i <= t;i++) {        if(cap[s][i] - flow[s][i]) ok = false;    }    for(int i = s;i < t;i++) if(cap[i][t] - flow[i][t]) ok = false;    if(!ok) puts("NO");    else {        puts("YES");        for(int i = 0;i < m;i++) {            printf("%d\n",flow[uu[i]][vv[i]] + low[i]);        }    }}int main() {    scanf("%d%d",&n,&m);    s = 0; t = n + 1;    memset(cap,0,sizeof(cap));    for(int i = 0;i < m;i++) {        int u,v,l,c; scanf("%d%d%d%d",&u,&v,&l,&c);        low[i] = l;        cap[u][v] += c - l;        cap[s][v] += l;        cap[u][t] += l;        uu[i] = u; vv[i] = v;    }    solve();    return 0;}