1/7 epa10804298 Russian President Vladimir Putin (L) and Moscow Mayor Sergei Sobyanin (R) explore the Manezh Metro Station exhibition before a ceremony to launch passenger traffic on the Line D3 of Moscow Central Diameters via video link at the Manezh Central Exhibition Hall in Moscow, Russia, 17 August 2023. The 85-kilometer-long D3 will link Saint Petersburg and Kazan lines (Zelenograd - Ramenskoye). The Moscow Central Diameters (MCD) is a system of commuter rail lines linking Moscow to its remote suburbs. EPA/KRISTINA KORMILITSYNA/SPUTNIK/KREMLIN POOL -- MANDATORY CREDIT--