size_t m, size_t k, size_t n,
size_t Block_size, size_t group, size_t key,
size_t size_row, size_t size_col, size_t NB_groups ){
size_t m, size_t k, size_t n,
size_t Block_size, size_t group, size_t key,
size_t size_row, size_t size_col, size_t NB_groups ){