def mt(N, S, A):
    dp = [float('inf')] * N
    dp[0] = A[0]

    for i in range(N):
        if i + 1 < N:
            dp[i + 1] = min(dp[i + 1], dp[i] + A[i + 1])

        dc = set()
        for j in range(i, N):
            dc.add(S[j])
            if j + 1 < N:
                ndc = dc | {S[j + 1]}
                if len(dc) < len(ndc):
                    dp[j + 1] = min(dp[j + 1], dp[i] + A[j + 1])
            else:
                break

    return dp[N - 1]


import sys

input = sys.stdin.read
data = input().splitlines()
N = int(data[0])
S = data[1]
A = list(map(int, data[2:N + 2]))

print(mt(N, S, A))

import sys
from collections import defaultdict

def calculateAns(N, M, parents, latency, q, queries):
    tree = defaultdict(list)
    for i in range(M):
        tree[parents[i]].append(i + 2)
    
    power = [0] * (N + 1)
    for i in range(1, N + 1):
        if i == 1:
            power[i] = float('inf')
        else:
            parent = parents[i - 2]
            power[i] = latency[i - 1] ^ latency[parent - 1]

    subtree_power = [0] * (N + 1)

    def dfs(node):
        total_power = power[node]
        for child in tree[node]:
            total_power = min(total_power, dfs(child))
        subtree_power[node] = total_power
        return total_power

    dfs(1)

    result = 0
    for query in queries:
        result = (result + subtree_power[query]) % (10**9 + 7)

    return result

def main():
    N = int(sys.stdin.readline().strip())
    M = int(sys.stdin.readline().strip())
    parents = []
    for _ in range(M):
        parents.append(int(sys.stdin.readline().strip()))
    latency = []
    for _ in range(N):
        latency.append(int(sys.stdin.readline().strip()))
    q = int(sys.stdin.readline().strip())
    queries = []
    for _ in range(q):
        queries.append(int(sys.stdin.readline().strip()))
    result = calculateAns(N, M, parents, latency, q, queries)
    print(result)

if __name__ == "__main__":
    main()

  N = int(input().strip())  
s = input().strip()       
print(-1 if s is None else len(set(s))) 

 A, B = map(int, input().strip().split())
print((A // B) ** 3)                                                                                                    
cube//wipro