#include <iostream>
#include <math.h>
using namespace std;

int main() {
    double x, y;
    cin >> x >> y;
    if (x>M_PI_2 && y>M_PI_2)
        cout << sin(x)+cos(y) << endl;
    else if (x<(-M_PI_2) && y <(-M_PI_2))
        cout << sin(y) << endl;
    else if ((-M_PI_2)<=x && x<=M_PI_2 && (-M_PI_2)<=y && y<=M_PI_2 )
        cout << x+y << endl;
    else
        cout << "Error input" << endl;
    return 0;
}