#include < iostream> using namespace std; int main() { int a = 0; int b = 0; int sum = 0; unsigned count = 0; cin > > a > > b; for (; a < = b; ++a) { if (a % 3 == 0) { count++; sum += a; } } if (count > 0) { cout < < "avg sum of numbers = " < < (double)sum / count; } else { cout < < "there are no numbers that are divisible by three"; } return 0; }