#include <stdio.h>

typedef struct NEURON {
    double output;
    struct NEURON *input_neuron;
} neuron;

int main(int argc, char **argv)
{
    neuron x, y;

    x.output =  1.0; y.output = 10.0;

    x.input_neuron = &y;
    y.input_neuron = &x;

    printf("x.output=%f\n", x.output);
    printf("y.output=%f\n", y.output);
    printf("x.output=%f\n", x.input_neuron->input_neuron->
                        output);
    printf("y.output=%f\n", y.input_neuron->input_neuron->
                        output);
    printf("x.output=%f\n", x.input_neuron->input_neuron->
                        input_neuron->input_neuron->output);
    printf("y.output=%f\n", y.input_neuron->input_neuron->
                        input_neuron->input_neuron->output);

    return 0;
}