package contest200722;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

public class D {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		// a b c d
		// min(a+d, b, c)?
		long[] a = new long[]{nl(), nl(), nl(), nl(), nl()};
		long min = Long.MAX_VALUE;
		for(int i = 0;i < 5;i++){
			if(a[i] < min){
				min = a[i];
			}
		}
		
		long ans = 0;
		for(int arg = 0;arg < 5;arg++){
			if(a[arg] == min){
				long[] b = new long[4];
				for(int i = 0;i < 4;i++){
					b[i] = a[(arg+i+1)%5];
				}
				
				// x a b c d
				long AD = b[0] + b[3] - min;
				long B = b[1];
				long C = b[2];
				
				long low = 0, high = Math.min(AD, Math.min(B, C)) + 1;
				while(high - low > 1){
					long h = high+low>>1;
					long er = Math.max(AD-h, 0) + Math.max(B-h, 0) + Math.max(C-h, 0);
					if(er >= min){
						low = h;
					}else{
						high = h;
					}
				}
				ans = Math.max(ans, min+low);
			}
		}
		out.println(ans);
		
//		for(long a = 0;a <= 10;a++){
//			for(long b = 0;b <= 10;b++){
//				for(long c = 0;c <= 10;c++){
//					long max = 0;
//					for(long A = 0;A <= 10;A++){
//						for(long B = 0;B <= 10;B++){
//							for(long C = 0;C <= 10;C++){
//								if(A+B <= a && B+C <= b && C+A <= c){
//									max = Math.max(max, A+B+C);
//								}
//							}
//						}
//					}
//					long[] d = {a, b, c};
//					Arrays.sort(d);
//					if(max != d[0]+d[1]){
//						tr(a, b, c, max);
//					}
//				}
//			}
//		}
	}
	
	void run() throws Exception
	{
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);
		
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
//		Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){
//			@Override
//			public void run() {
//				long s = System.currentTimeMillis();
//				solve();
//				out.flush();
//				if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
//			}
//		};
//		t.start();
//		t.join();
	}
	
	public static void main(String[] args) throws Exception { new D().run(); }
	
	private byte[] inbuf = new byte[1024];
	public int lenbuf = 0, ptrbuf = 0;
	
	private int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}
	
	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private double nd() { return Double.parseDouble(ns()); }
	private char nc() { return (char)skip(); }
	
	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
	
	private int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private long[] nal(int n)
	{
		long[] a = new long[n];
		for(int i = 0;i < n;i++)a[i] = nl();
		return a;
	}
	
	private char[][] nm(int n, int m) {
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}
	
	private int[][] nmi(int n, int m) {
		int[][] map = new int[n][];
		for(int i = 0;i < n;i++)map[i] = na(m);
		return map;
	}
	
	private int ni() { return (int)nl(); }
	
	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }
}