#include <bits/stdc++.h>
template <class t>
inline void read(t &s) {
  s = 0;
  register int f = 1;
  register char c = getchar();
  while (!isdigit(c)) {
    if (c == '-') f = -1;
    c = getchar();
  }
  while (isdigit(c)) s = (s << 3) + (s << 1) + (c ^ 48), c = getchar();
  s *= f;
  return;
}
template <class t, class... A>
inline void read(t &x, A &...a) {
  read(x);
  read(a...);
}
template <class t>
inline void write(t x) {
  if (x < 0) putchar('-'), x = -x;
  int buf[21], top = 0;
  while (x) buf[++top] = x % 10, x /= 10;
  if (!top) buf[++top] = 0;
  while (top) putchar(buf[top--] ^ '0');
  return;
}
inline void setIn(std::string s) {
  freopen(s.c_str(), "r", stdin);
  return;
}
inline void setOut(std::string s) {
  freopen(s.c_str(), "w", stdout);
  return;
}
inline void setIO(std::string s = "") {
  setIn(s + ".in");
  setOut(s + ".out");
  return;
}
template <class t>
inline bool ckmin(t &x, t y) {
  if (x > y) {
    x = y;
    return 1;
  }
  return 0;
}
template <class t>
inline bool ckmax(t &x, t y) {
  if (x < y) {
    x = y;
    return 1;
  }
  return 0;
}
inline int lowbit(int x) { return x & (-x); }
long double f[105], g[105];
int to[105];
inline int id(int x, int y) {
  if (x & 1) return (10 - x) * 10 + 11 - y;
  return (10 - x) * 10 + y;
}
signed main(void) {
  register int x;
  for (int i = 1; i <= 10; ++i)
    for (int j = 1; j <= 10; ++j) {
      read(x);
      if (x) to[id(i, j)] = id(i - x, j);
    }
  for (int i = 0; i <= 100; ++i) g[i] = 1e18;
  f[100] = 0;
  for (int i = 94; i <= 99; ++i) f[i] = 6;
  for (int i = 93; i; --i) {
    for (int j = 1; j <= 6; ++j) f[i] += std::min(f[i + j], g[i + j]) + 1;
    f[i] /= 6.0;
    if (to[i]) ckmin(g[i], f[to[i]]);
  }
  std::printf("%.99Lf\n", std::min(f[1], g[1]));
  return 0;
}
