#include <stdlib.h>
#include <stdio.h>

int get10(double x)
{
    return pow(10,floor(log10(x)));
}

int main(int argc, const char * argv[])
{
    for(int i = 1; i < 100000000; i*= 10)
    {
        printf("%10d:  %10d\n",i-1,get10(i-1));
        printf("%10d:  %10d\n",i,get10(i));
    }
}