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;
struct Fast { Fast() { cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20);} } fast;
 
long long mod = 1000000007;
 
long long div(long long a, long long b, long long c){
    return b / c - (a - 1) / c;
}
 
void print_binary(long long a) {
    for (int i = 31; i >= 0; i--) {
        cout << (a >> i & 1);
    }
    cout << endl;
}
 
int main() {
    int k, s, sum = 0, ans = 0;
    cin >> k >> s;
    while(k > 1){
        k = k / s;
        sum++;
    }
    if (k % s == 0){
        cout << sum <<endl;
        return 0;
    }
    cout << sum + 1 << endl;
}