#include <stdio.h>

#define M_G 9.81

int main()
{
    /*Variables*/
    double mu = 0.2;
    double m = 5.0;
    double p = 20.0;
    
    double a = (p-mu*m*M_G)/m;
    
    printf("Acceleration a=%f(m/s^2)\n",a);
    return 0;
    }