import sys
import math as mas

X,Y=map(int,input().split())
x,y=map(int,input().split())
t=max(X,Y)
if X==Y and x==y and x<X:t+=1
print(t)

#for i in sys.stdin:
#	a,b=map(int,i.split())
#	print(gcd(a,b),lcm(a,b))