public void solve(int testNumber, InputReader in, OutputWriter out) {
long n = in.nextInt();
long t = 2;
long sum = 0;
for (int i = 0; i < n; i++) {
sum += t;
t *= 2;
}
out.println(sum);
}
public void solve(int testNumber, InputReader in, OutputWriter out) {
int N = in.nextInt();
long[] c = new long[N];
String[] s = new String[N];
for (int i = 0; i < N; i++) {
c[i] = in.nextLong();
}
for (int i = 0; i < N; i++) {
s[i] = in.nextLine();
}
long[][] dp = new long[N][2];
dp[0][0] = 0;
dp[0][1] = c[0];
for (int i = 1; i < N; i++) {
dp[i][0] = dp[i][1] = Long.MAX_VALUE;
if (dp[i - 1][0] != Long.MAX_VALUE && s[i].compareTo(s[i - 1]) >= 0) {
dp[i][0] = Math.min(dp[i][0], dp[i - 1][0]);
}
if (dp[i - 1][1] != Long.MAX_VALUE && s[i].compareTo(Strings.reverse(s[i - 1])) >= 0) {
dp[i][0] = Math.min(dp[i][0], dp[i - 1][1]);
}
if (dp[i - 1][0] != Long.MAX_VALUE && Strings.reverse(s[i]).compareTo(s[i - 1]) >= 0) {
dp[i][1] = Math.min(dp[i][1], dp[i - 1][0] + c[i]);
}
if (dp[i - 1][1] != Long.MAX_VALUE
&& Strings.reverse(s[i]).compareTo(Strings.reverse(s[i - 1])) >= 0) {
dp[i][1] = Math.min(dp[i][1], dp[i - 1][1] + c[i]);
}
}
long ans = Math.min(dp[N - 1][0], dp[N - 1][1]);
if (ans == Long.MAX_VALUE) ans = -1;
out.println(ans);
}