#include<bits/stdc++.h>
using namespace std;
typedef pair< int , int >PII;

vector< PII >deltas(vector< int >X) {
    vector< PII >vd;
    for (int i = 0; i+1 < X.size(); i++) {
        if (X[i]+1 < X[i+1]) {
            vd.emplace_back(X[i+1]-X[i]-1, i);
        }
    }
    return vd;
}

void impossible() {
    cout << -1 << "\n";
    exit(0);
}

int main() {
//    ios::sync_with_stdio(false);
//    cin.tie(0);

    int n, l;
    cin >> n >> l;

    vector< int >A(n+2);
    A[0] = 0;
    A[n+1] = l+1;
    for (int i = 1; i <= n; i++) cin >> A[i];

    vector< int >B(n+2);
    B[0] = 0;
    B[n+1] = l+1;
    for (int i = 1; i <= n; i++) cin >> B[i];

    vector< PII >da = deltas(A);
    vector< PII >db = deltas(B);

    long long ans = 0;
    for (int i = db.size()-1; i >= 0; i--) {
        vector< PII >fromA;
        int sum = 0;
        while (sum < db[i].first) {
            assert(!da.empty());
//            if (da.empty()) impossible();
            sum += da.back().first;
            fromA.push_back(da.back());
            da.pop_back();
        }

        if (sum != db[i].first) impossible();

        int mn = fromA.back().second;
        int mx = fromA.front().second;
        mn = min(mn, db[i].second);
        mx = max(mx, db[i].second);

        ans += mx-mn;
    }

    if (!da.empty()) {
        impossible();
    }

    cout << ans << "\n";


    return 0;
}

#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define mkp make_pair
#define vi vector<int>
#define pii pair<int,int>
#define FI(n) FastIO::read(n)
#define FO(n) FastIO::write(n)
#define ull unsigned long long
#define mst(a,b) memset(a,b,sizeof(a))
#define foR(i,k,j) for(int i=(k);i>=(j);i--)
#define For(i,k,j) for(int i=(k);i<=(j);i++)
#define Foe(i,u) for(int i=lst[u],v=e[i].v;i;i=e[i].nxt,v=e[i].v)
#define IOS ios::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define Fin(s) freopen(s,"r",stdin)
#define Fout(s) freopen(s,"w",stdout)
#define file(s) Fin(s".in"),Fout(s".out")
#define INF ((1<<30)-1)
#define int long long
const int P=1e9+7; //
using namespace std;
template<typename T>inline void ckmax(T &a,T b) {(a<b)&&(a=b);}
template<typename T>inline void ckmin(T &a,T b) {(a>b)&&(a=b);}
inline int mul(int a,int b) {return 1ull*a*b%P;}
inline int add(int a,int b) {return a+b>=P?a+b-P:a+b;}
inline int sub(int a,int b) {return a-b>=0?a-b:a-b+P;}
inline void mulmod(int &a,int b) {a=mul(a, b);}
inline void addmod(int &a,int b) {((a+=b)>=P)&&(a-=P);}
inline void submod(int &a,int b) {((a-=b)<0)&&(a+=P);}
inline int ksm(int a,int b) {int ans=1; for(;b;b>>=1) {if(b&1) ans=1ll*ans*a%P;a=1ll*a*a%P;}return ans;}
inline void fprint(const int &x,char c=' ') {fprintf(stderr,"%d%c",x,c);}
inline void fprint(const pii &x,char c='\n') {fprintf(stderr,"%d %d%c",x.first,x.second,c);}
inline void fprint(const int *f,const int &n,char c='\n') {for(int i=1;i<=n;i++) fprint(f[i]); fprintf(stderr,"%c",c);}
inline void fprint(const vector<int> &f,char c='\n') {for(int i=0;i<(int)f.size();i++) fprint(f[i]); fprintf(stderr,"%c",c);}
inline int inv(int a) {return ksm(a,P-2);}
namespace FastIO {
  const int SIZE=1<<16; char buf[SIZE],obuf[SIZE],str[64]; int bi=SIZE,bn=SIZE,opt;
  int read(char *s) {
    while (bn) {for (;bi<bn&&buf[bi]<=' ';bi++);if (bi<bn) break; bn=fread(buf,1,SIZE,stdin),bi=0;}
    int sn=0;while (bn) {for (;bi<bn&&buf[bi]>' ';bi++) s[sn++]=buf[bi];if (bi<bn) break; bn=fread(buf,1,SIZE,stdin),bi=0;}s[sn]=0;return sn;
  }
  bool read(int& x) {if(x)x=0;int bf=0,n=read(str); if(!n) return 0; int i=0; if (str[i]=='-') bf=1,i=1; for(x=0;i<n;i++) x=x*10+str[i]-'0'; if(bf) x=-x; return 1;}
  void write(int x) {
    if(!x) obuf[opt++]='0'; else {if(x<0) obuf[opt++]='-',x=-x;int sn=0; while(x)str[sn++]=x%10+'0',x/=10;for (int i=sn-1;i>=0;i--) obuf[opt++]=str[i];}
    if (opt>=(SIZE>>1)){fwrite(obuf,1,opt,stdout); opt=0;}
  }
  void write(char x) {obuf[opt++]=x;if (opt>=(SIZE>>1)){fwrite(obuf,1,opt,stdout); opt=0;}}
	void Fflush() {if (opt) fwrite(obuf,1,opt,stdout); opt=0;}
};	
inline int read() {int x; FI(x); return x;}
const int MN=1e5+5;
int n,f[MN],ned[MN];
vi ans; int now,X,Y;
void doit(int x) {
	if(x==0) X++;
	if(x==1) Y++;
	if(x==2) X+=Y;
	if(x==3) Y+=X;
	ans.pb(x+1);
//	cerr<<X<<' '<<Y<<endl;
}
signed main() {
	#ifndef ONLINE_JUDGE
		freopen("pro.in","r",stdin);
		freopen("pro.out","w",stdout);
	#endif
	f[0]=f[1]=1; For(i,2,87) f[i]=f[i-1]+f[i-2];
	int n=read(),mx=-1;
	foR(i,87,0) {
		while(n>=f[i]) {
			if(mx==-1) mx=i;
			n-=f[i];	
//			cerr<<mx<<' '<<i<<endl;
			ned[mx-i]++;
		}
	}
//	cerr<<"?"<<endl;
//cerr<<mx<<endl;
	now=(mx&1); 
	For(i,0,mx) {
		while(ned[i]) {
			doit(now);	
			ned[i]--;
		}
		doit(now+2); now^=1;
		
	}
	cout<<ans.size()<<endl;
	for(auto it:ans) {
		printf("%d\n",it);	
	}
	return FastIO::Fflush(),0;
}
