private static Integer generateFibonacciSequence(int pituus) {
		int sumOfEvenFibonacciSequenceIntegers = 0;
		int previousInteger = 1;
		int nextInteger = 2;
		int tmp;
		for (int i = 0; i < pituus; i++) {
			if (nextInteger < 4000000) {
				if (nextInteger % 2 == 0) {
					sumOfEvenFibonacciSequenceIntegers+=nextInteger;
				}
				tmp = nextInteger;
				nextInteger = previousInteger + nextInteger;
				previousInteger = tmp;
							}
			else {
				break;
			}
		}
		return sumOfEvenFibonacciSequenceIntegers;
	}