import std.stdio, std.conv, std.functional, std.string; import std.algorithm, std.array, std.container, std.range, std.typecons; import std.bigint, std.numeric, std.math, std.random; import core.bitop; string FMT_F = "%.10f"; static File _f; void file_io(string fn) { _f = File(fn, "r"); } static string[] s_rd; T _RD(T = long)() { while(!s_rd.length) s_rd = readln.chomp.split; string res = s_rd[0]; s_rd.popFront; return res.to!T; } T _RD(T = long)(File f) { while(!s_rd.length) s_rd = f.readln.chomp.split; string res = s_rd[0]; s_rd.popFront; return res.to!T; } T[] _RDA(T = long)(T fix = 0) { auto r = readln.chomp.split.to!(T[]); r[] += fix; return r; } T[] _RDA(T = long)(File f, T fix = 0) { auto r = f.readln.chomp.split.to!(T[]); r[] += fix; return r; } T RD(T = long)() { if (_f.isOpen) return _RD!T(_f); else return _RD!T; } T[] RDA(T = long)(T fix = 0) { if (_f.isOpen) return _RDA!T(_f, fix); else return _RDA!T(fix); } size_t[] MAKE_IDX(alias less = "a < b", Range)(Range range) { auto idx = new size_t[](range.length); makeIndex!(less)(range, idx); return idx;} size_t MIN_POS(alias less = "a < b", Range)(Range range) { auto r = minPos!(less)(range); return range.length - r.length; } void chmin(T)(ref T x, T y) { x = min(x, y); } void chmax(T)(ref T x, T y) { x = max(x, y); } bool inside(T)(T x, T b, T e) { return x >= b && x < e; } T lcm(T)(T x, T y) { return x * (y / gcd(x, y)); } long mod = 10^^9 + 7; //long mod = 998_244_353; //long mod = 1_000_003; void moda(T)(ref T x, T y) { x = (x + y) % mod; } void mods(T)(ref T x, T y) { x = ((x + mod) - (y % mod)) % mod; } void modm(T)(ref T x, T y) { x = (x * y) % mod; } void modpow(T)(ref T x, T y) { if (!y) { x = 1; return; } auto t = x; x.modpow(y>>1); x.modm(x); if (y&1) x.modm(t); } void modd(T)(ref T x, T y) { y.modpow(mod - 2); x.modm(y); } T binarySearch(alias pred, T)(T ok, T ng) { while (abs(ok-ng) > 1) { auto mid = (ok+ng)/2; if (unaryFun!pred(mid)) ok = mid; else ng = mid; } return ok; } struct SegTree(T) { T delegate(const(T), const(T)) f; T[] data; T init; this(T[] _data, T delegate(const(T), const(T)) _f, T _init) { f = _f; init = _init; size_t n = 1; while (n < _data.length) n *= 2; data.length = n*2-1; foreach (i; 0.._data.length) data[i+n-1] = _data[i]; foreach (i; _data.length..n) data[i+n-1] = _init; foreach_reverse (i; 0..n-1) data[i] = f(data[i*2+1], data[i*2+2]); } T query(size_t l, size_t r) const { size_t n = (data.length+1) / 2; l += n-1; r += n-1; T res = f(init, data[l]); while (l < r) { if ((l & 1) == 0) res = f(res, data[l]); if ((r & 1) == 0) res = f(res, data[r-1]); l = l/2; r = (r-1)/2; } return res; } void update(size_t i, T v) { i += (data.length+1) / 2 - 1; data[i] = v; while (i != 0) { i = (i-1)/2; data[i] = f(data[i*2+1], data[i*2+2]); } } } void main() { auto N = RD; auto A = RDA; bool ok = true; foreach (i; 0..N) { if (A[i] == 0) ok = false; } if (!ok) { writeln(0); } else { auto b = new long[2][](N); foreach (i; 0..N) { b[i] = [A[i], 0]; } long[2] func(in long[2] x, in long[2] y) { long[2] z; if (x[1] == 1) z = x; else if (y[1] == 1) z = y; else { z[0] = x[0] * y[0]; z[1] = z[0] >= 10^^9 ? 1 : 0; } return z; } auto st = new SegTree!(long[2])(b, &func, [1, 0]); auto cnt = new long[](N+1); auto cnt2 = new long[](N+1); foreach (i; 0..N) { bool f(long j) { auto x = st.query(i, j+1); return x[1] == 0; } auto r = binarySearch!(f)(i, N); cnt[i] = r - i + 1; --cnt2[i]; debug writeln("r:", min(i+cnt[i], N)); ++cnt2[min(i+cnt[i], N)]; } debug writeln(cnt2); foreach (i; 0..N) { cnt2[i+1] += cnt2[i]; } debug writeln(cnt); debug writeln(cnt2); long ans = 1; foreach (i; 0..N) { debug writeln("cnt[i]:", cnt[i]); auto x = A[i]; x.modpow(cnt[i]); ans.modm(x); cnt[i+1] += cnt[i] + cnt2[i]; } writeln(ans); } stdout.flush; debug readln; }