https://www.acmicpc.net/problem/2442
import 'dart:io';
void main(){
int? n=int.parse(stdin.readLineSync()!);
for(var i=1;i<=n;i++){
var res='';
for(var k=0;k<n-i;k++){
res+=" ";
}
for(var j=0;j<(i-1)*2+1;j++){
res+='*';
}
print(res);
}
}