String solutions in $AdS_3\times S^3\times S^3\times S^1$ with $B$-field

We consider strings living in $AdS_3\times S^3\times S^3\times S^1$ with nonzero $B$-field. By using specific ansatz for the string embedding, we obtain a class of solutions corresponding to strings moving in the whole ten dimensional space-time. For the $AdS_3$ subspace, these solutions are given in terms of incomplete elliptic integrals. For the two three-spheres, they are expressed in terms of Lauricella hypergeometric functions of many variables. The conserved charges, i.e. the string energy, spin and angular momenta, are also found.