Next month, many theaters in the Cinemark chain will be showing It's a Mad, Mad, Mad, Mad World on April 10 and/or April 13. You can find out if and when one near you is screening it over on this page but you should probably ignore where it gives the running time as 205 minutes. We who are experts on this wonderful film know of no print in existence that is that long.
The longest is the extended version that was assembled for the recent Criterion release. That one was 197 minutes and I doubt Cinemark is even running that one. More likely, they'll have the 154 minute cut, which some feel is the preferred version. Stanley Kramer, who produced and directed it, sometimes felt that way.