#include <stdio.h>
#include <math.h>
int main()
{
    double d,p,r,m;
    d=300000;
    p=6000;
    r=0.01;
    m=[log10(p)-log10(p-d*r)]/log10(1+r);
    printf("m=%.2f\n",m);
    return 0;
}