static void Main()
{
var ss = new StreamScanner(new StreamReader(Console.OpenStandardInput()));
var sw = new StreamWriter(Console.OpenStandardOutput())
{
AutoFlush = false
};
new Program().Solve(ss, sw);
sw.Flush();
}
void Solve(StreamScanner ss, StreamWriter sw)
{
//---------------------------------
const long ??? = 2000000000000;
var A = ss.Next(long.Parse);
var K = ss.Next(long.Parse);
if (K == 0)
{
sw.WriteLine(??? -A);
return;
}
var day = 0;
while (A < ???)
{
A += 1 + K * A;
day++;
}
sw.WriteLine(day);
//---------------------------------
}