``` alias integer = size_t; import std.stdio : writefln;
void main() { auto arr = [ [5, 15], // 20 [2, 3, 2, 3], // 10 [3, 6, 2, 9], // 20 ]; foreach (integer i, row; arr) { double total = 0.0; foreach (e; row) total += e; auto avg = total / row.length; writefln("AVG [row=%d]: %.2f", i, avg); } } ```