COW, 183 bytes

oomMMMmoOMMMmoOoomMMMmoOMMMmOomOoMMMmoOmoOmoOMMMMMMmoOMMMmOomOoMMMmoOmoOmoOMMMMMMmoOMMMmOoMOOmOomOomOomOomOomOoMOOMOomoOmoOMOOMoOmoOmoOMOOMoOmoOmoOMOoMMMOOOmooOOOmooOOOmooMMMmoomoOOOM

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Returns the smaller integer. It increases and decreases both, the first to reach 0 (with precedence to the decreasing one) is the smaller.

[0]: n to be decreased   [1]: n   [2]: m to be increased   [3]: m   [4]: n to be increased   [5]: n   [6]: m to be decreased   [7]: m

i=>=>i=>=<<=>>>==>=<<=>>>==>=<    | set up memory cells as above
[                                 | loop until a cell reaches 0
    <<<<<<[->>[+>>[+>>-=*]*]*]=   | [0]-- [2]++ [4]++ [6]--
]>o                               | print the redundant copy of the smaller

moo ]    mOo <    MOo -    OOO *    OOM i
MOO [    moO >    MoO +    MMM =    oom o