`ƯCLN(16, 60) = 2^2 = 4`
`→ ƯC(16, 90) = {1; 2; 4}`
`ƯCLN(18, 77) = 1`
`→ ƯC(18, 77) = {1}`
`ƯCLN(18, 90) = 2 . 3^2 = 18`
`→ ƯC(18, 90) = {1: 3: 6: 18}`
`ƯCLN(18, 30, 42) = 2 . 3 = 6`
`→ ƯC(18, 30, 42) = {1; 2; 3; 6}`
`ƯCLN(26, 39, 48) = 1`
`→ ƯC(26, 39, 48) = {1}`