#include <math.h>
#include <stdio.h>

#define PI 3.141592653859

int main(void)
{
    int n,c;
    int li[10000], ai[10000];
    float afi[10000];
    int s,a,ao;
    int i,j;
    float x,y,af,afo;
    int boo=0;
    
    while (scanf("%d %d\n", &n, &c) > 0)
    {
	if(boo)
	    printf("\n");
	boo = 1;
	x = 0;
	y = 0;
	for(i=0; i<n; i++)
	{
	    scanf("%d", &(li[i]));
	    afi[i] = PI/2;
	    ai[i] = 180;
	    y += li[i];
	}
	for(i=0; i<c; i++)
	{
	    scanf("%d %d\n", &s, &a);
	    ao = a;
	    a -= ai[s];
	    af = (a*PI)/180;
	    for(j=s; j<n; j++)
	    {
		afo = afi[j];
		afi[j] += af;
		x += li[j]*(cos(afi[j]) - cos(afo));
		y += li[j]*(sin(afi[j]) - sin(afo));
	    }
	    printf("%.2f %.2f\n", x, y);
	    
	}
    }
}