NZEC error

Hello I am new to this platform. This is my first solution. I am getting a NZEC error.
Please advice.
import java.util.Scanner;

class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int t = sc.nextInt();
for(int i=0;i<t;i++) {
sc.nextLine();
String s=sc.nextLine();
int c=0;
for(int k=0;k<s.length();k=k+2) {
if(s.charAt(k)==s.charAt(k+1)) {
System.out.println(“no”);
c=1;
break;
}
}
if(c==0) {
System.out.println(“yes”);
}
}
}
}

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