import strutils, sequtils

proc cin: string =
    while true:
        let tmp = readChar stdin
        if not isSpaceAscii tmp:
            safeAdd result, tmp
        elif tmp != '\r': break

proc main =
    let N, M = parseInt cin()
    var cups = "/xxx/"
    cups[N] = 'o'
    
    for i in 0 ..< M:
        let P, Q = parseInt cin()
        swap(cups[P], cups[Q])
    
    echo find(cups, 'o')

main()