java版本的：
package com.string;
import java.util.ArrayList;
import java.util.Scanner;
public class MyString {
public static void main(String[] args) {
Scanner in=new Scanner(System.in);
int num=in.nextInt();
String[] aStrings=new String[num];
for (int i = 0; i < num; i++) {
aStrings[i]=in.next();
}
in.close();
System.out.println(isGood(aStrings));
}
public static int isGood(String[] arg)
{
ArrayList<String> list=new ArrayList<String>();
int num=arg.length;
//System.out.println(num);
if (num<=1) {
return -1;
}
int number=0;
for (int i = 0; i < num; i++) {
char[] c=arg[i].toCharArray();
int n=c.length;
String str1=String.valueOf(c[0]);
String str2=String.valueOf(c[n-1]);
list.add(str1);
list.add(str2);
}
//// for(int i=0;i<list.size();i++)
//// {
//// System.out.print(list.get(i));
////
//// }
// System.out.println();
for(int i=0;i<(list.size()/2-1);i++)
{
if (list.get(2*i+1).equals(list.get(2*i+2))) {
number+=1;
}
}
if (number==num-1) {
return 1;
}else
return -1;
}
}
