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 = 998244353; //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 main() { auto N = RD; auto P = RD; auto fib = new long[](N); fib[0] = 0; fib[1] = 1; foreach (i; 2..N) { fib[i] = P; fib[i].modm(fib[i-1]); fib[i].moda(fib[i-2]); } long ans; long s; foreach_reverse (i; 0..N) { s.moda(fib[i]); long t = s; t.modm(fib[i]); ans.moda(t); } writeln(ans); stdout.flush; debug readln; }