#include<bits/stdc++.h>
#define lowbit(x) ((x)&-(x))
using namespace std;
struct ios{
    inline char gc(){
        static const int IN_LEN=1<<18|1;
        static char buf[IN_LEN],*s,*t;
        return (s==t)&&(t=(s=buf)+fread(buf,1,IN_LEN,stdin)),s==t?-1:*s++;
    }
    template <typename _Tp> inline ios & operator >> (_Tp&x){
        static char ch,sgn; ch = gc(), sgn = 0;
        for(;!isdigit(ch);ch=gc()){if(ch==-1)return *this;sgn|=ch=='-';}
        for(x=0;isdigit(ch);ch=gc())x=x*10+(ch^'0');
        sgn&&(x=-x); return *this;
    }
}io;
#define cin io
mt19937 Rnd(20080123);
int n,E;
typedef struct{
	typedef struct{
		int key;
		long long x,tag;
		int ls,rs,siz;
	}Tree;
	Tree t[2000011];
	int root,idx;
	void push_up(int p)
	{
		t[p].siz = t[t[p].ls].siz + t[t[p].rs].siz + 1;
	}
	void Add(int p,long long val)
	{
		if(!p)
			return;
		t[p].x += val,t[p].tag += val;
	}
	void push_down(int p)
	{
		Add(t[p].ls,t[p].tag),Add(t[p].rs,t[p].tag),t[p].tag = 0;
	}
	void split(int p,int k,int& l,int& r)
	{
		if(!p)
			return l = r = 0,void();
		push_down(p);
		if(t[p].x < k)
			return l = p,split(t[p].rs,k,t[p].rs,r),push_up(p);
		else
			return r = p,split(t[p].ls,k,l,t[p].ls),push_up(p);
	}
	void split_siz(int p,int k,int& l,int& r)
	{
		if(!p)
			return l = r = 0,void();
		push_down(p);
		if(t[t[p].ls].siz + 1 <= k)
			return l = p,split_siz(t[p].rs,k - t[t[p].ls].siz - 1,t[p].rs,r),push_up(p);
		else
			return r = p,split_siz(t[p].ls,k,l,t[p].ls),push_up(p);
	}
	int merge(int x,int y)
	{
		if(!x || !y)
			return x|y;
		if(t[x].key < t[y].key)
			return push_down(x),t[x].rs = merge(t[x].rs,y),push_up(x),x;
		else
			return push_down(y),t[y].ls = merge(x,t[y].ls),push_up(y),y;
	}
	int New(long long val)
	{
		t[++idx].x = val;
		t[idx].key = Rnd();
		t[idx].siz = 1;
		return idx;
	}
}FHQ;
FHQ T1;
typedef struct{
	long long t[1000011];
	void add(int p,int val)
	{
		while(p)
		{
			t[p] += val;
			p -= lowbit(p);
		}
	}
	long long ask(int p)
	{
		long long res = 0;
		while(p <= n)
		{
			res += t[p];
			p += lowbit(p);
		}
		return res;
	}
}BIT;
BIT T2;
typedef struct{
	long long mn,tag;
}SGT;
SGT t[4000011];
void Cost(int p,long long x)
{
	t[p].mn -= x,t[p].tag += x;
}
void push_up(int p)
{
	t[p].mn = min(t[p << 1].mn,t[p << 1 | 1].mn);
}
void push_down(int p)
{
	Cost(p << 1,t[p].tag),Cost(p << 1 | 1,t[p].tag),t[p].tag = 0;
}
void down(int p,int l,int r,int ll,int rr,int k)
{
	if(l <= ll && rr <= r)
		return Cost(p,k);
	push_down(p);
	int mid = ll + rr >> 1;
	if(l <= mid)
		down(p << 1,l,r,ll,mid,k);
	if(mid < r)
		down(p << 1 | 1,l,r,mid + 1,rr,k);
	push_up(p);
}
int cnt;
void upt(int p,int ll,int rr)
{
	if(t[p].mn >= 0)
		return;
	if(ll == rr)
	{
		// cerr << "Insert " << ll << "\n";
		cnt++;
		t[p].mn = LLONG_MAX;
		int val = T2.ask(ll);
		int l,r;
		T1.split(T1.root,val,l,r);
		T1.split_siz(r,1,val,r);
		T1.root = T1.merge(l,r);
		return;
	}
	int mid = ll + rr >> 1;
	push_down(p),upt(p << 1,ll,mid),upt(p << 1 | 1,mid + 1,rr),push_up(p);
}
int a[1000011],b[1000011],c[1000011];
int st[1000011],top;
long long ans;
int main()
{
	cin >> n >> E;
	ans = (1ll + n) * n / 2;
	for(int i = 1;i <= 4 * n;i++)
		t[i].mn = E;
	for(int i = 1;i <= n;i++)
		cin >> a[i];
	for(int i = 1;i <= n;i++)
		cin >> b[i];
	for(int i = 1;i <= n;i++)
		c[i] = min(a[i],b[i]);
	for(int i = 1;i <= n;i++)
	{
		T2.add(i,b[i] - a[i]);
		int l,r,p = T1.New(0);
		T1.split(T1.root,0,l,r);
		T1.root = T1.merge(T1.merge(l,p),r);
		T1.Add(T1.root,b[i] - a[i]);
		if(a[i] > b[i])
			down(1,1,i,1,n,a[i] - b[i]);
		down(1,i,i,1,n,c[i]);
		while(top && c[st[top]] < c[i])
		{
			down(1,st[top - 1] + 1,st[top],1,n,c[i] - c[st[top]]);
			top--;
		}
		st[++top] = i;
		upt(1,1,n);
		// T1.Print(T1.root);
		// cerr << T1.t[T1.root].x << "\n";
		T1.split(T1.root,0,l,r);
		ans -= cnt + T1.t[l].siz;
		// cerr << cnt << " " << T1.t[l].siz << "\n";
		T1.root = T1.merge(l,r);
	}
	assert(ans >= 0);
	printf("%lld\n",ans);
	return 0;
}