#include<bits/stdc++.h>
#define Add(x,y) (x+y>=mod)?(x+y-mod):(x+y)
#define lowbit(x) x&(-x)
#define pi pair<ll,ll>
#define pii pair<ll,pair<ll,ll>>
#define iip pair<pair<ll,ll>,ll>
#define ppii pair<pair<ll,ll>,pair<ll,ll>>
#define fi first
#define se second
#define full(l,r,x) for(auto it=l;it!=r;it++) (*it)=x
#define Full(a) memset(a,0,sizeof(a))
#define open(s1,s2) freopen(s1,"r",stdin),freopen(s2,"w",stdout);
using namespace std;
typedef double db;
typedef unsigned long long ull;
typedef long long ll;
bool Begin;
inline ll read(){
    ll x=0,f=1;
    char c=getchar();
    while(c<'0'||c>'9'){
        if(c=='-')
          f=-1;
        c=getchar();
    }
    while(c>='0'&&c<='9'){
        x=(x<<1)+(x<<3)+(c^48);
        c=getchar();
    }
    return x*f;
}
inline void write(ll x){
	if(x<0){
		putchar('-');
		x=-x;
	}
	if(x>9)
	  write(x/10);
	putchar(x%10+'0');
}
bool End;
ll X1,Y1,X2,Y2,D;
ll get(ll X,ll Y,ll D){
    if(X<Y)
      swap(X,Y);
    if(D>=X+Y)
      return (X+1)*(Y+1);
    if(D>=X)
      return (X+1)*(Y+1)-(X+Y-D)*(X+Y-D+1)/2;
    if(D>=Y)
      return Y*(Y+1)/2+(Y+1)*(D-Y+1);
    return (D+1)*(D+2)/2;
}
ll solve(ll X1,ll Y1,ll X2,ll Y2,ll D){
	ll ans=0;
	if(X1>X2)
	  swap(X1,X2);
	if(Y1>Y2)
	  swap(Y1,Y2);
	if(X1<0&&X2>0)
      return solve(1,Y1,-X1,Y2,D)+solve(0,Y1,X2,Y2,D);
	if(Y1<0&&Y2>0)
	  return solve(X1,1,X2,-Y1,D)+solve(X1,0,X2,Y2,D);
	if(X1<0)
	  return solve(-X2,Y1,-X1,Y2,D);
	if(Y1<0)
	  return solve(X1,-Y2,X2,-Y1,D);
	ans+=get(X2,Y2,D);
	if(X1)
	  ans-=get(X1-1,Y2,D);
	if(Y1)
	  ans-=get(X2,Y1-1,D);
	if(X1&&Y1)
	  ans+=get(X1-1,Y1-1,D);
	return ans;
}
int main(){
//	open("manhattan.in","manhattan.out");
    X1=read(),Y1=read(),X2=read(),Y2=read(),D=read();
    write(solve(X1,Y1,X2,Y2,D));
    return 0;
}