import java.io.IOException; import java.io.InputStream; import java.math.BigInteger; import java.util.Arrays; import java.util.NoSuchElementException; public class Main { public static void main(String[] args) { new Main().run(); } long gcd(long a,long b) { return a==0?b:gcd(b%a,a); } long h(long a,long b) { return (gcd(a,b)+(a+1)*(b+1))/2+1; } long g(long d,long x,long y) { if (x<0||y<0||d<0) return 0; if (x+y<=d) return (x+1)*(y+1); return (x+1)*(y+1)-h(x+y-d,x+y-d)+x+y-d+1; } long f(long x1,long y1,long d,long x2,long y2) { x2=Math.min(x2, x1+d); y2=Math.min(y2, y1+d); return g(d,x2-x1,y2-y1); } long f_brute(long x1,long y1,long d,long x2,long y2) { long ret=0; for (long x=x1;x<=x1+d;++x) { for (long y=y1;y<=y1+d;++y) { long dx=x-x1; long dy=y-y1; if (dx+dy>d) continue; if (x<=x2&&y<=y2) ++ret; } } return ret; } void run() { FastScanner sc=new FastScanner(); long x1=sc.nextLong(); long y1=sc.nextLong(); long x2=sc.nextLong(); long y2=sc.nextLong(); long d=sc.nextLong(); x2=Math.min(x2, +d); y2=Math.min(y2, +d); x1=Math.max(x1, -d); y1=Math.max(y1, -d); long ans=0; if (x1<=0&&0<=x2&&y1<=0&&0<=y2)++ans; ans+=f(Math.max(+x1, 1),Math.max(0,+y1),d-(Math.max(+x1, 1)+Math.max(0,+y1)),+x2,+y2);//第1象限 ans+=f(Math.max(-x2, 0),Math.max(1,+y1),d-(Math.max(-x2, 0)+Math.max(1,+y1)),-x1,+y2);//第2象限 ans+=f(Math.max(-x2, 1),Math.max(0,-y2),d-(Math.max(-x2, 1)+Math.max(0,-y2)),-x1,-y1);//第3象限 ans+=f(Math.max(+x1, 0),Math.max(1,-y2),d-(Math.max(+x1, 0)+Math.max(1,-y2)),+x2,-y1);//第4象限 System.out.println(ans); } void tr(Object...objects) {System.out.println(Arrays.deepToString(objects));} } class FastScanner { private final InputStream in = System.in; private final byte[] buffer = new byte[1024]; private int ptr = 0; private int buflen = 0; private boolean hasNextByte() { if (ptr < buflen) { return true; }else{ ptr = 0; try { buflen = in.read(buffer); } catch (IOException e) { e.printStackTrace(); } if (buflen <= 0) { return false; } } return true; } private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;} private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;} public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();} public String next() { if (!hasNext()) throw new NoSuchElementException(); StringBuilder sb = new StringBuilder(); int b = readByte(); while(isPrintableChar(b)) { sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } public long nextLong() { if (!hasNext()) throw new NoSuchElementException(); long n = 0; boolean minus = false; int b = readByte(); if (b == '-') { minus = true; b = readByte(); } if (b < '0' || '9' < b) { throw new NumberFormatException(); } while(true){ if ('0' <= b && b <= '9') { n *= 10; n += b - '0'; }else if(b == -1 || !isPrintableChar(b)){ return minus ? -n : n; }else{ throw new NumberFormatException(); } b = readByte(); } } public int nextInt() { long nl = nextLong(); if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException(); return (int) nl; } public double nextDouble() { return Double.parseDouble(next());} }