pseudo.java

// Make a sum and count variable

for (/* i from 0 to 2 */) {
  // read user input
  // add to sum
  // increment count
}

//print sum and sum / count

//reset sum and count
//get user input
while (/* user input isn't -999 */) {
  // add to sum
  // increment count
  // get user input 
}

//print sum and sum / count