#include<cstdio>
const int N=100010,M=4000000;
int n,m,i,x,y,a[N],g[N],v[N<<1],nxt[N<<1],ed,f[N],h[N];
int l[M],r[M],tag[M],T[N],tot;bool val[M],fin[N];
inline void read(int&a){char c;while(!(((c=getchar())>='0')&&(c<='9')));a=c-'0';while(((c=getchar())>='0')&&(c<='9'))(a*=10)+=c-'0';}
inline void add(int x,int y){v[++ed]=y;nxt[ed]=g[x];g[x]=ed;}
inline void rev(int d,int p,int x){if(!x||d<0)return;tag[x]^=p;if(p>>d&1){int t=l[x];l[x]=r[x];r[x]=t;}
}
inline void pb(int d,int x){if(tag[x])rev(d-1,tag[x],l[x]),rev(d-1,tag[x],r[x]),tag[x]=0;}
int build(int d,int p){int x=++tot;if(d<0)return val[x]=1,x;if(p>>d&1)r[x]=build(d-1,p);else l[x]=build(d-1,p);return x;
}
int merge(int d,int p,int x,int y){if(!y)return x;if(!x){rev(d,p,y);return y;}int z=++tot;if(d<0)return val[z]=1,z;pb(d,x),pb(d,y);if(p>>d&1)l[z]=merge(d-1,p,l[x],r[y]),r[z]=merge(d-1,p,r[x],l[y]);else l[z]=merge(d-1,p,l[x],l[y]),r[z]=merge(d-1,p,r[x],r[y]);return val[z]=val[l[z]]&val[r[z]],z;
}
inline int mex(int x){int t=0;for(int i=m;~i;i--){pb(i,x);if(!val[l[x]])x=l[x];else x=r[x],t|=1<<i;}return t;
}
void dfs(int x,int y){for(int i=g[x];i;i=nxt[i])if(v[i]!=y)dfs(v[i],x),h[x]^=f[v[i]];if(!a[x])T[x]=build(m,h[x]);for(int i=g[x];i;i=nxt[i])if(v[i]!=y)T[x]=merge(m,h[x]^f[v[i]],T[x],T[v[i]]);f[x]=mex(T[x]);
}
void cal(int x,int y,int z){z^=f[x]^h[x];if(!a[x]&&!z)fin[x]=1;for(int i=g[x];i;i=nxt[i])if(v[i]!=y)cal(v[i],x,z);
}
int main(){for(read(n),i=1;i<=n;i++)read(a[i]);for(i=1;i<n;i++)read(x),read(y),add(x,y),add(y,x);while((1<<m)<=n)m++;m--;dfs(1,0);if(!f[1])return puts("-1"),0;for(cal(i=1,0,f[1]);i<=n;i++)if(fin[i])printf("%d\n",i);return 0;
}