725B - Food on the Plane - CodeForces Solution

s = input()
r = int(s[:-1]) - 1
c = s[-1]

ans = (r // 4) * (12 + 4)
r -= r // 4 * 4
if r % 2 == 1:
    ans += 6 + 1
ans += "fedabc".index(c) + 1
print(ans)