#include <stdio.h>
#include <math.h>
#include <cstdlib>
#include <iostream>
using namespace std;
int main()
{
	float a = 0.2,c=0.7;
	float d = 0;
	do
	{
		d += pow(4, a * c) - pow(sin(a + c), 2);
		c += 0.3;
	} while (c<2.1);
	cout << "d=" << d;
	return 0;
}