import sys
input = sys.stdin.readline

now=0
ANS=0
X=int(input())
for i in range(7):
    now+=2
    ANS+=2
    if X==now:
        break
    now+=2
    ANS+=2
    if X==now:
        break
    now-=1
    ANS+=1
    if X==now:
        break
    now-=1
    ANS+=1
    if X==now:
        break
    now+=2
    ANS+=2
    if X==now:
        break
    now-=1
    ANS+=1
    if X==now:
        break
    now-=1
    ANS+=1
    if X==now:
        break
print(ANS)