#include <stdio.h>

int main()
{
  float average_int(int, int);
  int a = 5;
  int b = 4;
  printf("%d と %d の平均は %f です\n", a, b, average_int(a, b));
}

float average_int(int x, int y)
{
  float m;
  m = (x+y)/2.0;
  return m;
}