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

#define MAX 16384
#define EPS 1e-5

struct vector {
  double x,y;
  int uhel;
};

vector a[2*MAX];
int pravy[MAX];

int n,c;

void recompute(int index) {
  vector &levy=a[2*index];
  vector &pravy=a[2*index+1];
  //prepocteme uhly
  a[index].uhel=levy.uhel+pravy.uhel;

  //  a[2*index], a[2*index+1]
  if (pravy.x==0.0 && pravy.y==0.0) a[index]=a[2*index];
  else {
    //    printf("Rec at %d, uhel %d\n",index,levy.uhel);

    double uhel=levy.uhel*3.1415926535/180.0;
    double c=cos(uhel),s=sin(uhel);
    a[index].x=levy.x+pravy.x*c-pravy.y*s;
    a[index].y=levy.y+pravy.x*s+pravy.y*c;
  }

  if (index>1) recompute(index/2);
}

int main(void) {
  int first=1;

  for (int i=MAX-1;i>0;i--) {
    int p=2*i+1;
    while (p<MAX) p*=2;    
    pravy[i]=p;
  }

  while (n=-1,scanf("%d %d",&n,&c),n!=-1) {

    if (!first) putchar('\n');
    first=0;

    for (int i=0;i<MAX;i++) {a[MAX+i].x=a[MAX+i].y=0.0; a[MAX+i].uhel=0;}
    for (int i=0;i<n;i++) {
      int len;
      scanf("%d",&len);
      a[MAX+i].y=len;
    }
    for (int i=MAX-1;i>0;i--) {
      a[i].uhel=0;
      a[i].x=0;
      a[i].y=a[2*i].y+a[2*i+1].y;
    }

    while (c--) {
      int kloub,uhel;
      scanf("%d %d",&kloub,&uhel);
      a[MAX+kloub-1].uhel=uhel-180;

      recompute((MAX+kloub-1)/2);

      printf("%.2f %.2f\n",a[1].x+EPS,a[1].y+EPS);
    }
  }

  return 0;
}