import java.io.*;
import java.util.*;
public class Divide {
private int small, big;
public void smallBig(int a, int b) {
if (a > b) {
big = a;
small = b;
}
else {
big = a;
small = b;
}
}
public int GCD(int a, int b) {
smallBig(a, b);
while (big % small != 0) {
small = small - 1;
}
return small;
}
public int GCD2(int a, int b) {
smallBig(a, b);
int r;
while (small != 0) {
r = small;
small = big % small;
big = r;
}
return big;
}
public boolean isPrime(int n) {
int num = n-1;
while (n % num != 0) {
num = num-1;
}
if (n > 1) {
return (num == 1);
}
else {
return false;
}
}
//rewriting GCD using for loop
public int GCDfor(int a, int b) {
smallBig(a, b);
for( ; big%small != 0; small --) {
}
return small;
}
public string reverse(String s) {
for (int index = s.length() - 1; index >= 0;
}
}