int sensor_check ()
{
int rfront, rback, lfront, lback, return_value=0, check=0;
rfront=right_front();
lfront=left_front();
rback=right_back();
lback=left_back();

printf("Sensor Check\n");

if (lfront==1)
{
return_value=1;
check=1;
if (rfront==1) return_value=2;
}

if (check==0)
{
if (rfront==1)
{
return_value=3;
check=1;
if (rback==1) return_value=4;
}
}

if (check==0)
{
if (rback==1)
{
return_value=5;
check=1;
if (lback==1) return_value=6;
}
}

if (check==0)
{
if (lback==1)
{
return_value=7;
if (lfront==1) return_value=8;
}
}

return return_value;
}