#include<bits/stdc++.h>
using namespace std;
char buf1[1<<21],*p1=buf1+(1<<21),*p2=buf1+(1<<21);
char _getchar(){
    if(p1==p2)fread(p1=buf1,1<<21,1,stdin);
    return *p1++;
}
int read(){
    int x=0;char c=_getchar();
    while(c<'0'||c>'9')c=_getchar();
    while(c>='0'&&c<='9')x=x*10+(c^'0'),c=_getchar();
    return x;
}
char buf2[1<<21],*p3=buf2,*p4=buf2+(1<<21);
void _putchar(char x){
    if(p3==p4)fwrite(p3=buf2,1<<21,1,stdout);
    *p3++=x;
}
void write(int x){
    if(!x)return _putchar('0'),_putchar(' '),void();
    int num[25],len=0;
    while(x)num[++len]=x%10,x/=10;
    while(len)_putchar(num[len--]^'0');
    _putchar(' ');
}
#define ll long long
const ll mod=1e9+7;
int n,W;
int a[1000005],pos[1000005],val[1000005];
int st[1000005],top;
vector<int> edge[1000005];
int deg[1000005];
ll fac[1000005],inv[1000005];
int vis[1000005];
ll power(ll a,ll p){
    ll res=1;
    while(p){
        if(p&1)res=res*a%mod;
        p>>=1;
        a=a*a%mod;
    }
    return res;
}
int mx[4000005],mxp[4000005],mn[4000005],mnp[4000005],tree[4000005];
void build(int k,int l,int r){
    tree[k]=r-l+1;
    if(l==r){
        mx[k]=mn[k]=val[l];
        mxp[k]=mnp[k]=l;
        return;
    }
    int mid=l+r>>1;
    build(k*2,l,mid);
    build(k*2+1,mid+1,r);
    if(mx[k*2]>=mx[k*2+1])mx[k]=mx[k*2],mxp[k]=mxp[k*2];
    else mx[k]=mx[k*2+1],mxp[k]=mxp[k*2+1];
    if(mn[k*2]<=mn[k*2+1])mn[k]=mn[k*2],mnp[k]=mnp[k*2];
    else mn[k]=mn[k*2+1],mnp[k]=mnp[k*2+1];
}
void erase(int k,int l,int r,int x){
    tree[k]--;
    if(l==r){
        mn[k]=0x3f3f3f3f,mnp[k]=0;
        return;
    }
    int mid=l+r>>1;
    if(x<=mid)erase(k*2,l,mid,x);
    else erase(k*2+1,mid+1,r,x);
    if(mn[k*2]<=mn[k*2+1])mn[k]=mn[k*2],mnp[k]=mnp[k*2];
    else mn[k]=mn[k*2+1],mnp[k]=mnp[k*2+1];
}
int querymx(int k,int l,int r,int x,int y){
    if(l>=x&&r<=y)return mxp[k];
    int mid=l+r>>1;
    if(y<=mid)return querymx(k*2,l,mid,x,y);
    if(x>mid)return querymx(k*2+1,mid+1,r,x,y);
    int res1=querymx(k*2,l,mid,x,y),res2=querymx(k*2+1,mid+1,r,x,y);
    if(val[res1]>=val[res2])return res1;
    else return res2;
}
int query(int k,int l,int r,int x,int y){
    if(l>=x&&r<=y)return tree[k];
    int mid=l+r>>1;
    if(y<=mid)return query(k*2,l,mid,x,y);
    if(x>mid)return query(k*2+1,mid+1,r,x,y);
    return query(k*2,l,mid,x,y)+query(k*2+1,mid+1,r,x,y);
}
pair<int,int> querymn(int k,int l,int r,int x,int y){
    if(l>=x&&r<=y)return make_pair(mn[k],mnp[k]);
    int mid=l+r>>1;
    if(y<=mid)return querymn(k*2,l,mid,x,y);
    if(x>mid)return querymn(k*2+1,mid+1,r,x,y);
    return min(querymn(k*2,l,mid,x,y),querymn(k*2+1,mid+1,r,x,y));
}
ll solve(int l,int r){
    if(l>r)return 1;
    int p=querymx(1,1,n,l,r);
    int all=query(1,1,n,l,r),cnt=0;
    while(1){
        auto q=querymn(1,1,n,l,r);
        if(q.first+val[p]<=W)cnt++,erase(1,1,n,q.second);
        else break;
    }
    // int p=l;
    // for(int i=l;i<=r;i++)if(val[i]>val[p])p=i;
    // int all=0,cnt=0;
    // for(int i=l;i<=r;i++)if(!vis[i])all++;
    // for(int i=l;i<=r;i++)if(!vis[i]&&val[i]+val[p]<=W)cnt++,vis[i]=1;
    return solve(l,p-1)*solve(p+1,r)%mod*fac[all]%mod*inv[all-cnt]%mod;
}
int main(){
    n=read(),W=read();
    for(int i=1;i<=n;i++)pos[n-(a[i]=read())+1]=i;
    for(int i=1;i<=n;i++)val[pos[i]]=read();
    fac[0]=1;
    for(int i=1;i<=n;i++)fac[i]=fac[i-1]*i%mod;
    inv[n]=power(fac[n],mod-2);
    for(int i=n;i>=1;i--)inv[i-1]=inv[i]*i%mod;
    build(1,1,n);
    write(solve(1,n));_putchar('\n');
    for(int i=1;i<=n;i++){
        if(top&&val[i]+val[st[1]]>W){
            int l=1,r=top;
            while(l<r){
                int mid=l+r+1>>1;
                if(val[st[mid]]+val[i]<=W)r=mid-1;
                else l=mid;
            }
            edge[a[st[l]]].push_back(a[i]),deg[a[i]]++;
        }
        while(top&&val[st[top]]<=val[i])top--;
        st[++top]=i;
    }
    top=0;
    for(int i=n;i>=1;i--){
        if(top&&val[i]+val[st[1]]>W){
            int l=1,r=top;
            while(l<r){
                int mid=l+r+1>>1;
                if(val[st[mid]]+val[i]<=W)r=mid-1;
                else l=mid;
            }
            edge[a[i]].push_back(a[st[l]]),deg[a[st[l]]]++;
        }
        while(top&&val[st[top]]<=val[i])top--;
        st[++top]=i;
    }
    priority_queue<int,vector<int>,greater<int>> que;
    for(int i=1;i<=n;i++)if(!deg[i])que.push(i);
    while(!que.empty()){
        int x=que.top();que.pop();
        write(x);
        for(int y:edge[x])if(!--deg[y])que.push(y);
    }
    _putchar('\n');
    fwrite(buf2,p3-buf2,1,stdout);
    // cerr<<"time: "<<clock()*1000./CLOCKS_PER_SEC<<"ms"<<endl;
    return 0;
}