/* Author: Nguyen Chi Thanh - High School for the Gifted - VNU.HCM (i2528) */ #include <bits/stdc++.h> using namespace std; #define int long long #define ull unsigned long long #define ld long double #define pii pair<int, int> #define fi first #define se second #define __builtin_popcount __builtin_popcountll #define all(x) (x).begin(), (x).end() #define BIT(x, i) (((x) >> (i)) & 1) #define MASK(x) ((1ll << (x))) #define debug(a, l, r) for (int _i = (l); _i <= (r); ++_i) cout << (a)[_i] << ' '; cout << '\n'; const int MAXN = 1005; int n, dp[MAXN][5]; pii intervals[MAXN]; void init() { cin >> n; for (int i = 1; i <= n; ++i) { pii &cur = intervals[i]; cin >> cur.fi >> cur.se; } } int floor_div(int a, int b) { if (b < 0) a = -a, b = -b; if (a >= 0) return a / b; return - ((-a + b - 1) / b); } int ceil_div(int a, int b) { if (b < 0) a = -a, b = -b; if (a >= 0) return (a + b - 1) / b; return - ((-a) / b); } // Count numer of a_i in [l, r] such that a_i % m = k int cnt_div(int l, int r, int m, int k) { assert(k < m && l <= r); int t_min = ceil_div(l - k, m); int t_max = floor_div(r - k, m); if (t_min > t_max) return 0; return t_max - t_min + 1; } void solve() { for (int j = 0; j < 5; ++j) dp[1][j] = cnt_div(intervals[1].fi, intervals[1].se, 5, j); for (int i = 1; i < n; ++i) { for (int j = 0; j < 5; ++j) { for (int cur_rem = 0; cur_rem < 5; ++cur_rem) { int nxt_rem = (j + cur_rem) % 5; int mul = cnt_div(intervals[i + 1].fi, intervals[i + 1].se, 5, cur_rem); dp[i + 1][nxt_rem] += dp[i][j] * mul; } } } // debug(dp[n], 0, 4); int res = 0; for (int i = 0; i < 5; ++i) { int mul = i * i * i * i + 2 * i * i; mul %= 5; res += (mul + 1) * dp[n][i]; } cout << res; } signed main() { #ifdef NCTHANH freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout); #endif ios_base::sync_with_stdio(0); cin.tie(nullptr); cout.tie(nullptr); init(); solve(); return 0; }