https://www.acmicpc.net/problem/2438
import java.util.*;
class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int N = sc.nextInt();
for (int i = 1; i <= N; i++) {
for (int t = 1; t <= i; t++) {
System.out.printf("*");
}
System.out.printf("\n");
}
sc.close();
}
}