#include <stdio.h>

int abs(int a);

int main()
{
  int magic = 8;
  int count = 0;

  char q = 'S'; //ex

  while ( q != '7' ) {
    scanf("%c", &q);
    count++;
  }
  count -= 2;

  printf("%d\n", abs(magic - count) );

  return (0);
}

int abs(int a)
{
  if ( a < 0 ) {
    return a * -1;
  } else {
    return a;
  }
}