The Holmes children are fighting over who amongst them is the cleverest.
Mycroft asked Sherlock and Eurus to find value of f(n), where f(1) = 1 and for n ≥ 2, f(n) is the number of distinct ordered positive integer pairs (x, y) that satisfy x + y = n and gcd(x, y) = 1. The integer gcd(a, b) is the greatest common divisor of a and b.
Sherlock said that solving this was child's play and asked Mycroft to instead get the value of . Summation is done over all positive integers d that divide n.
Eurus was quietly observing all this and finally came up with her problem to astonish both Sherlock and Mycroft.
She defined a k-composite function Fk(n) recursively as follows:

She wants them to tell the value of Fk(n) modulo 1000000007.
A single line of input contains two space separated integers n (1 ≤ n ≤ 1012) and k (1 ≤ k ≤ 1012) indicating that Eurus asks Sherlock and Mycroft to find the value of Fk(n) modulo 1000000007.
Output a single integer — the value of Fk(n) modulo 1000000007.
7 1
6
10 2
4
In the first case, there are 6 distinct ordered pairs (1, 6), (2, 5), (3, 4), (4, 3), (5, 2) and (6, 1) satisfying x + y = 7 and gcd(x, y) = 1. Hence, f(7) = 6. So, F1(7) = f(g(7)) = f(f(7) + f(1)) = f(6 + 1) = f(7) = 6.
#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
long long Euler(long long x) {
long long ans = x, i;
for(i = 2; i*i <= x; ++i) {
if(x%i == 0){
ans = ans - ans/i;
while(x%i == 0)x /= i;
}
}
if(x > 1) {
ans = ans - ans / x;
}
return ans;
}
int main() {
ios::sync_with_stdio(false);
long long n, k;
cin >> n >> k;
while(k>0 && n>1) {
if(k & 1) n = Euler(n);
k--;
}
cout << n % MOD << endl;
return 0;
}