//include <stdio.h>

int countDivisible(int value, int divisor)
{
    return(value - 1)/ divisor;
}

int main()
{
    int value , divisor;
    scanf ("%d" ,&value);
    scanf ("%d" , &divisor);
    
    printf("%d", countDivisible(value,divisor));
    return 0;
}