CodeForces 569A-Music

#include <iostream>#include <cstdio>#include <cmath>#include <cstdlib>#include <iomanip>#include <algorithm>#include <cctype>#include <stack>#include <queue>#include <string>#include <cstring>#include <iomanip>#include <set>#include <vector>#include <cstdio>#include <stack>#include <sstream>#include <cstring>#include <map>using namespace std;int main(){    int t,s,q,num=1;    cin>>t>>s>>q;    while(s*q<t)    {        num++;        s*=q;    }    cout<<num<<endl;    return 0;}