A = 'Hello';
B = ', ';
C = 'world';
D = strcat(A, B, C);

fun append_esclamation_mark(A, n)
{
	if n == none:
		n = 1;
	
	i = 0;
	while i < n:
		{	
			A = strcat(A, '!');
			i = i + 1;
		}

	return A;
}

print(append_esclamation_mark(D, 3), '\n');