#include<bits/stdc++.h>
#define de(x) cout<<#x<<"="<<x<<endl;
#define dd(x) cout<<#x<<"="<<x<<" ";
#define rep(i,a,b) for(int i=a;i<(b);++i)
#define repd(i,a,b) for(int i=a;i>=(b);--i)
#define repp(i,a,b,t) for(int i=a;i<(b);i+=t)
#define ll long long
#define mt(a,b) memset(a,b,sizeof(a))
#define fi first
#define se second
#define inf 0x3f3f3f3f
#define INF 0x3f3f3f3f3f3f3f3f
#define pii pair<int,int>
#define pdd pair<double,double>
#define pdi pair<double,int>
#define mp(u,v) make_pair(u,v)
#define sz(a) (int)a.size()
#define ull unsigned long long
#define ll long long
#define pb push_back
#define PI acos(-1.0)
#define qc std::ios::sync_with_stdio(false)
#define db double
#define all(a) a.begin(),a.end()
const int mod = 1e9+7;
const int maxn = 2e2+5;
const double eps = 1e-6;
using namespace std;
bool eq(const db &a, const db &b) { return fabs(a - b) < eps; }
bool ls(const db &a, const db &b) { return a + eps < b; }
bool le(const db &a, const db &b) { return eq(a, b) || ls(a, b); }
ll gcd(ll a,ll b) { return a==0?b:gcd(b%a,a); };
ll lcm(ll a,ll b) { return a/gcd(a,b)*b; }
ll kpow(ll a,ll b) {ll res=1;a%=mod; if(b<0) return 1; for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
ll read(){ll x=0,f=1;char ch=getchar();while (ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}while (ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}return x*f;
}
int n,m,s,t,tot;
int b[maxn*maxn],c[maxn*maxn],in[maxn],out[maxn];
int pre[maxn],dis[maxn];
int q[maxn],l,r;
struct edge{int v,w,nt;
}e[maxn*maxn];
void init(){tot = 0;mt(pre,-1);mt(in,0);mt(out,0);
}
void addedge(int u,int v,int w){e[tot].v=v;e[tot].w=w;e[tot].nt=pre[u];pre[u]=tot++;e[tot].v=u;e[tot].w=0;e[tot].nt=pre[v];pre[v]=tot++;
}
bool bfs(){mt(dis,-1);dis[s]=0;l = r = 0;q[r++] = s;while(l<r){int u=q[l++];for(int i=pre[u];~i;i=e[i].nt){int v=e[i].v,w=e[i].w;if(dis[v]==-1&&w>0){dis[v]=dis[u]+1;q[r++] = v;}}}return dis[t]!=-1;
}
int dfs(int u,int cp){if(u==t||!cp) return cp;int tmp=cp;for(int i=pre[u];~i;i=e[i].nt){int v=e[i].v,w=e[i].w;if(dis[v]==dis[u]+1&&w>0){int tt=dfs(v,min(tmp,w));e[i].w-=tt;e[i^1].w+=tt;tmp-=tt;if(tmp<=0) return cp;}}dis[u]=inf;return cp-tmp;
}
int dinic(){int ret = 0;while(bfs()) ret+=dfs(s,inf);return ret;
}
int main(){int u,v;init();scanf("%d%d",&n,&m);rep(i,0,m) scanf("%d%d%d%d",&u,&v,&b[i],&c[i]),addedge(u,v,c[i]-b[i]),in[v] += b[i],out[u] += b[i];s = 0;t = n + 1;int ans = 0;rep(i,1,n+1) if(out[i] - in[i] > 0) addedge(i,t,out[i] - in[i]),ans += out[i] - in[i];else addedge(s,i,in[i] - out[i]);if(ans!=dinic())  return puts("NO"),0;puts("YES");rep(i,0,m) printf("%d\n",b[i] + e[i << 1 | 1].w);return 0;
}