// 20161027泰勒sin cos.cpp : 定義主控台應用程式的進入點。
//

#include "stdio.h"
#include<stdlib.h>
#include<ctype.h>
#include<math.h>
double fsin(double,double);
float fcos(float, float);
int main()
{

	char a[4];
	double angle, n;
	while (scanf("%s", a)!= EOF)
	{
		int pn = 1;
		scanf("%lf %lf", &angle, &n);
		int i = 0;
		while (a[i] != '\0')//to小字母
		{
			a[i] = tolower(a[i]);
			i++;
		}
		while (angle >180 || angle < 0)//角度轉換
		{
			if (angle >= 360)angle -= 360;
			if (angle <0)angle += 360;
			if (angle <= 360 && angle > 180)
			{
				angle -= 180;
				pn = -1;
			}
		}
		angle = angle*3.14 / 180;
		if (!strcmp(a, "sin"))
		{
			double ans = fsin(angle, n);
			printf("%.6lf\n",pn*ans);
		}
		else if (!strcmp(a, "cos"))
		{
			float ans = fcos(angle, n);
			printf("%.6f\n", pn*ans);
		}
		else
		{
			puts("Input Error.");
		}
	}
}

double fsin(double angle, double n)
{
	if (n == -1)return 0;
	double div = 1;
	for (int i = 1; i <= 2 * n + 1; i++)
		div *= i;
	double sum = pow(-1,n)*pow(angle, 2 * n + 1) /div;
	return (sum + fsin(angle,--n));
}
float fcos(float angle, float n)
{
	if (n == -1)return 0;
	float div = 1;
	for (int i = 1; i <= 2 * n; i++)
	{
		div *= i;
	}
	double sum = pow(-1, n)*pow(angle, 2 * n) / div;
	return sum + fcos(angle, --n);
}