
#include <stdio.h>

int main(void)
{
long long int X;
long long int XX = 100;
int count = 0;
  
    scanf("%lld", &X);

    while(XX < X){
      count += 1;
      XX = XX * 1.01;
    }

    
    printf("%d\n", count);
    
    return 0;
}
