Find total quantity sold of each product

Hi everyone,  I have product name in columns: A, C, E, D, G, I, K, M, O, Q, S, U, W, Y, AA, AC, AE, AG, AI, AK, AM, AO, AQ, AS, AU, AW, AY, BA, BC, BE, BG, and in columns B, D, F, H, J, L, N, P, R, ...