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 :

var i,a,b,max,day:longint;
begin
  for i:=1 to 7 do
    begin
      readln(a,b);
      if (a+b>max)and(a+b>8) then begin max:=a+b;day:=i;end;
    end;
  writeln(day);
end.