C++ :

#include <cstdio>
#include <cstdlib>
using namespace std;
int main()
{
	int array[8];
	int max=0;
	int maxday;
	for(int i=1;i<=7;i++)
	{
		int a,b;
		scanf("%d%d",&a,&b);
		array[i]=a+b;
		if(array[i]>max)
		{
			maxday=i;
			max=array[i];
		}
	}
	if(max<=8)
	{
		printf("0");
	}
	else
	{
		printf("%d",maxday);
	}
	//system("pause");
	return 0;
}

Pascal :

program p25857;
var a:array[1..7]of integer;
    i,x,y,max,day:integer;
    yes:boolean;
begin
  for i:=1 to 7 do 
      begin 
        readln(x,y);
        a[i]:=x+y;
      end;
  yes:=true;
  max:=0;
  for i:=1 to 7 do
     if (a[i]>8)then
       begin
       yes:=false;
       if a[i]>max then
         begin 
           max:=a[i];
           day:=i;
         end;
       end;
    if yes then writeln(0)
           else writeln(day);
  end.