#include<stdio.h>
int main()
{
int a1,b1,a2,b2,a3,b3,a4,b4,a5,b5,a6,b6,a7,b7;
scanf("%d %d\n%d %d\n%d %d\n%d %d\n%d %d\n%d %d\n%d %d",&a1,&b2,
&a2,&b2,&a3,&b3,&a4,&b4,&a5,&b5,&a6,&b6,&a7,&b7);
int s1,s2,s3,s4,s5,s6,s7;
if(s1<=8&&s2<=8&&s3<=8&&s4<=8&&s5<=8&&s6<=8&&s7<=8)
printf("0");
else if(s1>8)
printf("1");
else if(s2>8)
printf("2");
else if(s3>8)
printf("3");
else if(s4>8)
printf("4");
else if(s5>8)
printf("5");
else if(s6>8)
printf("6");
else if(s7>8)
printf("7");
return 0;
}