fun learn(examples: Array<DoubleArray>) {

        var result  = Array(size, { DoubleArray(size, {0.0})})
        for (e in examples) {
            val matrix  = e.map { i -> e.map { j -> i*j } }
            for (i in 0 until matrix.size) {
                for (j in 0 until matrix[0].size) {
                    result[i][j] += matrix[i][j]
                }
            }
        }
        println("Learning done")

        for ( (i,row) in result.withIndex()) {
            neurons[i].weights = row
        }
    }