In java:

public static int birthday(List s, int d, int m) { // Write your code here

//m --> array lenght
//d --> total sum of lenght
//s --> array

Integer numberOfPossibleCombinations = 0;
Integer chocolateBarSize = s.size();

for (int i = 0; i < chocolateBarSize ; i++){  

    List<Integer> sumList = s.stream().skip(i).limit(m).collect(Collectors.toList());    
    if(m > sumList.size()){
        break;
    }

    System.out.print("sumList " + sumList);

    Integer sum = sumList.stream().mapToInt(Integer::intValue).sum();
    System.out.println("sum " + sum);

    if(sum == d){
        numberOfPossibleCombinations++;
    }
}

return numberOfPossibleCombinations;
}