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 a,i,x,y,d,max : byte;
begin
{assign(input,'unhappy.in'); reset(input);
assign(output,'unhappy.out'); rewrite(output); }
d := 0; max :=8;
for i := 1 to 7 do begin
readln(x,y);
a := x+y;
if a>max then
begin
max :=a; d := i;
end;
end;
writeln(d);
{close(input); close(output); }
end.