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

const double pi=3.14159265358979323;

int main(){
    int parts,cms;
    int *part,*rem;
    int len;
    char buff[65535];
    int pos;
    int c,i,u,p,li,ln;
    double ax,ay,l,fx,fy;

    c=' ';
    while(c!=-1){
    scanf("%d %d\n",&parts,&cms);
    part=(int*)malloc(parts*sizeof(int));
    rem=(int*)malloc(parts*sizeof(int));
    pos=0;
    for(i=0;i<parts;i++){
    	c=getchar();
	while(c!=' ' && c!=10){
	  buff[pos++]=c;
	  c=getchar();
	}
	buff[pos]=0;
	pos=0;	
	part[i]=atoi(buff);
	len+=part[i];
    }
    rem[parts-1]=part[parts-1];
    for(i=parts-2;i>=0;i--){
      rem[i]=rem[i+1]+part[i];
    }
    
    ax=0.0;
    ay=0.0;
    l=90.0;
    li=0;
    for(i=0;i<cms;i++){
      scanf("%d %d",&p,&u);
      ln=rem[li]-rem[p];
      ay+=ln*sin(l*pi/180);
      ax+=ln*cos(l*pi/180);
      l=l+u-180.0;
      fy=ay+rem[p]*sin(l*pi/180);
      fx=ax+rem[p]*cos(l*pi/180);
      li=p;
      printf("%.2f %.2f\n",fx,fy);
    }

    c=getchar();
    if(c!=-1) putchar('\n');
    }
    return 0;
}