import java.util.*;
class Main
{
public static void main
(String[] args
) {
int N, k = 1;
double S = 10, T = 10;
Scanner input
= new Scanner
(System.
in); N = input.nextInt();
while (N > T)
{
S = S * 1.1;
T = S + T;
k++;
}
}
}
aW1wb3J0IGphdmEudXRpbC4qOwoKCmNsYXNzIE1haW4KewoJcHVibGljIHN0YXRpYyB2b2lkIG1haW4gKFN0cmluZ1tdIGFyZ3MpCgl7CgkJaW50IE4sIGsgPSAxOwoJCWRvdWJsZSBTID0gMTAsIFQgPSAxMDsKCQlTY2FubmVyIGlucHV0ID0gbmV3IFNjYW5uZXIoU3lzdGVtLmluKTsKICAgICAgICBOID0gaW5wdXQubmV4dEludCgpOwogICAgICAgIHdoaWxlIChOID4gVCkgCiAgICAgICAgewoJCQlTID0gUyAqIDEuMTsKCQkJVCA9IFMgKyBUOwoJCQlrKys7CgkJfQoJCVN5c3RlbS5vdXQucHJpbnQoayk7CgkJCgkJCgl9Cn0=