#include <iostream>
using namespace std;
long long int fact(int i)
{
     long double fact1;
    fact1 = 1;
    for (int j = 1; j <= (2 * i - 1); j++)
    {
        fact1 *= j;
    }
    return fact1;
    /*if (i <= 1) return 1;
    else
    return i * fact(i - 1);*/
}
double check(void)
{
    double value;
    while (!scanf_s("%lf", &value))
    {
        system("cls");
        rewind(stdin);
        printf("Please enter number:\n");

    }
    return value;
}
int main()
{
    double e, x,summ=0;
    int i;

    printf("e=");
    e=check();
    printf("x=");
    x = check();


    for (i = 1;; i++)
    {

        summ += (pow(-1, i-1) * pow(x, (2 * i - 1))) / fact(i);
        if (abs(sin(x)-summ)<= e)
        {

            printf("\nn=%d", i);
            break;
        }
    }

}