int currIndex = dnaStr.indexOf(stopCodon, startIndex+3);
    while(currIndex != -1){
        int diff = currIndex - startIndex;
        if(diff%3 ==0){

            return currIndex;


        } else{
            currIndex = dnaStr.indexOf(stopCodon, currIndex);
        }


    }
    return dnaStr.length();
}

public String findGene(String dna, int where){
    int startIndex = dna.indexOf("ATG", where);

    if(startIndex == -1){
        return "";

    }
    int taaIndex = findStopCodon(dna, startIndex, "TAA");
    int tagIndex = findStopCodon(dna, startIndex, "TAG");
    int tgaIndex = findStopCodon(dna, startIndex, "TGA");
    int minIndex = 0;

    if(taaIndex == -1 ||
            (tgaIndex != -1 && tgaIndex < taaIndex)){
        minIndex = tgaIndex;

    }else{
        minIndex = taaIndex;


    }
    if(minIndex == -1 || (tagIndex !=-1 && tagIndex<minIndex)){
        minIndex  = tagIndex;

    }
    if(minIndex == -1){

        return "";
    }
    if(minIndex+3 > dna.length()){
    return "";
}

    return dna.substring(startIndex, minIndex+3);
}

public void printAllGenes(String dna) {

    int startIndex = 0;

    while(true){

        System.out.println("yes");
        String currentGene = findGene(dna, startIndex);

        if(currentGene.isEmpty()){
            break;
        }

        System.out.println(currentGene);

        startIndex = dna.indexOf(currentGene, startIndex) + currentGene.length();
    }

}