from scipy.optimize import linprog
u,v,w,x,y=map(int,input().split())
d=(0,None)
print(int(-linprog([-1,-1,-1,-1,-1],[[1,0,0,1,1],[1,1,0,0,1],[1,1,1,0,0],[0,1,1,1,0],[0,0,1,1,1]],[u,v,w,x,y],bounds=(d,d,d,d,d)).fun + 0.001))