First example is the triple $(X,\pi,B_{0})$ where $X={{\bf R}}^{2n}/\Lambda,\,\,B_{0}={{\bf R}}^{n}/\Lambda^{\prime}$ are tori (here $\Lambda\simeq{{\bf Z}}^{2n},\,\,\Lambda^{\prime}\simeq{{\bf Z}}^{n}$ are lattices), projection $\pi:X\to B_{0}$ is an affine map of tori, and $X$ carries a constant symplectic form. Assuming that fibers of $\pi$ are connected we have $B_{0}=B=B^{sm}$. The monodromy representation is a homomorphism $\rho:\pi_{1}(B)\to{{\bf R}}^{n}\subset GL(n,{{\bf Z}})\ltimes{{\bf R}}^{n}$. Integral affine structure on $B$ depends on $n^{2}$ real parameters, which are coefficients of an invertible $n\times n$ matrix expressing a basis of the lattice $\Lambda^{\prime}\subset T_{x}B$ as a linear combination of generators of the lattice $(T_{x}B)^{{\bf Z}}\subset T_{x}B$, where $x\in B$ is an arbitrary point.