public class Foo {
    public static void main(String args[]) {
        int counter = 0;
        while(true) {
            counter++;
            if (counter % 5 == 0) {
                if (Math.random(4)+1 == 1) {
                    System.out.println("Found it after " + counter + " minutes");
                    break;
                }
            }
        }
    }
}