import math
x=[int(i) for i in input().split()]
m=0
for i in range(2):
    if x[i]<0:
        x[i]=-1*x[i]
    m+=x[i]
r=x[2]
rx=r*1.41421356
rz=math.ceil(rx)
m+=rz
print(m)
#x,y,r=map(int,input().split())