import sys a = sys.stdin.readlines() b = a[0].strip('\n').split(' ') #得到格子个数和颜色的种类 c = a[1].strip('\n').split(' ') #得到数字 d = a[2].strip('\n').split(' ') #得到颜色的序列 s = 0 for i in range(int(b[0])): for k in range(i+1,int(b[0])): for l in range(k+1,int(b[0])): if k-i ==l-k : if d[i] == d[l]: s += (i+l+2)*(int(c[i])+int(c[l]))
print(s)