#include #include using namespace std; const int MOD = 1000000007; struct Seq { long long len{0}, ns{0}, sL{0}, sR{0}, ans{0}; pair p1{-1, 0}, p2{-1, 0}; }; Seq concat(const Seq &A, const Seq &B) { Seq S; S.len = (A.len + B.len) % MOD; S.ns = (A.ns + B.ns) % MOD; S.p1 = A.p1.first >= 0 ? A.p1 : make_pair((B.p1.first + A.len) % MOD, B.p1.second); S.p2 = B.p2.first >= 0 ? make_pair((B.p2.first + A.len) % MOD, B.p2.second) : A.p2; S.sL = (A.sL + B.sL + B.ns*A.len) % MOD; S.sR = (A.sR + B.sR + A.ns*B.len) % MOD; S.ans = (A.ans + B.ans + A.sL*B.len + B.sR*A.len) % MOD; // Check if there's a new switch. if (A.p2.first >= 0 && B.p1.first >= 0 && A.p2.second != B.p1.second) { S.ns++; long long vL = A.p2.first + 1, vR = (B.len - B.p1.first + MOD) % MOD; S.sL = (S.sL + vL) % MOD; S.sR = (S.sR + vR) % MOD; S.ans = (S.ans + vL*vR) % MOD; } return S; } int K; string U; int solve() { cin >> K >> U; Seq S; for (int i = 0; i < K; i++) { Seq S2; if (U[i] == '.') { S2 = S; } else { S2.len = 1; if (U[i] != 'F') { S2.p1 = S2.p2 = make_pair(0, U[i]); } } S = concat(S, S2); } return S.ans; } int main() { int T; cin >> T; for (int t = 1; t <= T; t++) { cout << "Case #" << t << ": " << solve() << endl; } return 0; }