Help me in solving MAKEDIV3 problem

help
,
1

My issue

I am adding 0 for n>=2 but for test case n = 2 its failing. My O/P is 30 which is correct, it is divisible by 3 but not by 9

My code

#include <iostream>
#include <bits/stdc++.h>
#include <string>
#define ll long long
#define ld long double
using namespace std;

bool ispowerof2 ( ll num )
{
    if ( ( num & ( num - 1 ) ) == 0 )
        return 1;
    return 0;   
}

ll getSqrt(ll x) {
    ll lo = 0, hi = 1e9, c = 0;
    while(lo <= hi) {
        ll mid = (lo + hi) / 2;
        if((mid * mid) <= x) {
            c = mid;
            lo = mid + 1;
        } else hi = mid - 1;
    }
    return c;
}
 

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); 
    ll t;
    cin>>t;
    while(t--){
        ll n;
        cin>>n;
        string s ="3";
        n--;
        while(n>0){
            s+='0';
            n--;
        }
        cout<<s<<endl;
    }
	return 0;
}

Learning course: Jump from 2* to 3*
Problem Link: Make it Divisible Practice Problem in Jump from 2* to 3* - CodeChef

2

@ren0
u have to print odd number which is divisible by 3 and not by 9.