#include <stdio.h>


int main(void)
{
    int num = 0;
    int i = 0;
    int j = 0;
    //declaring vars

    do{
    printf("Enter a number between 5 and 20: " );
    scanf("%d", &num);
    getchar();
    }while(!(5 < num && 20 > num));
    //ask for a number until there's a valid input (5<num<20)

    for(i = 1; i < num + 1; i++){

        for(j = 0; j < i; j++){
            printf("*");
        }
        //prints * for the value of i
        printf("\n");
        //goes a row down
    }

    return 0;
}