cc

# div2 easy
class PalindromePrime():
    def count(self,L,R):
        return sum(str(x) == str(x)[::-1] and not any (x % i == 0 for i in range(2,x)) for x in range(L,R+1))

# div2 med
from itertools import permutations
class FourStrings():
    def shortestLength(self,a,b,c,d):
        def h(x,y):
            if y in x: return x
            for w in range(min(len(x),len(y)),0,-1):
                if x[-w:] == y[:w]:
                    return x + y[w:]
            return x+y
        return min(len(reduce(h, p)) for p in permutations([a,b,c,d]))

# div2 hard
from collections import deque
class PalindromePath():
    def shortestLength(self,n,a,b,c):
        sa = a+b
        sb = b+a
        conn = {(x,y):z for x,y,z in zip(sa,sb,c+c)}

        q = deque()
        dist = {}
        def push(s,d):
            q.append(s)
            dist[s] = d

        for i in range(n): push((i,i),0)
        for x,y in zip(sa,sb): push((x,y),1)

        while len(q) > 0:
            s = q.popleft()
            for i in range(n):
                for j in range(n):
                    if (i,j) not in dist and conn.get((s[0],i),"abc") == conn.get((j,s[1]),"def"):
                        push((i,j),dist[s]+2)

        return dist.get((0,1),-1)