Problem:
Score : 200 points

Problem Statement

Given is an integer N. Find the number of digits that N has in base K.

Notes

For information on base-K representation, see Positional notation - Wikipedia.

Constraints

All values in input are integers.

1 \leq N \leq 10^9

2 \leq K \leq 10

Input

Input is given from Standard Input in the following format:

N K

Output

Print the number of digits that N has in base K.

Sample Input 1

11 2

Sample Output 1

4

In binary, 11 is represented as 1011.

Sample Input 2

1010101 10

Sample Output 2

7

Sample Input 3

314159265 3

Sample Output 3

18

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include<bits/stdc++.h>
using namespace std;

#define rep(i, n) for (int i = 0; i < n; ++i)
#define all(x) (x).begin(),(x).end()
#define endl "\n"

using ll = long long;
using P = pair<int,int>;
using mp =  map<int,int>;

const int MOD = 1e9 + 7;

int main() {
	ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);

    int n, k;
    cin >> n >> k;

    ll ans = 0;
    while(n >= 1){
        n /= k;
        ans++;
    }

    cout << ans << endl;
    return 0;
}