The no-boundary wavefunction for slow-roll inflation on the 3-sphere exponentially favors a small universe, in sharp disagreement with observations. I will explain how this problem is resolved by changing the spatial topology to the 3-torus. The sum over geometries, computed using the theory of automorphic forms for GL(3), produces a wavefunction favoring a large inflating universe with N>250 e-folds. This will be an informal discussion based on the recent paper 2605.05317.