import core.bitop, std.algorithm, std.ascii, std.bigint, std.conv, std.math,
    std.functional, std.numeric, std.range, std.stdio, std.string, std.random,
    std.typecons, std.container, std.format;

// dfmt off
T lread(T = long)(){return readln.chomp.to!T();}
T[] aryread(T = long)(){return readln.split.to!(T[])();}
void scan(TList...)(ref TList Args){auto line = readln.split();
foreach (i, T; TList){T val = line[i].to!(T);Args[i] = val;}}
alias sread = () => readln.chomp();enum MOD = 10 ^^ 9 + 7;
alias PQueue(T, alias less = "a<b") = BinaryHeap!(Array!T, less);
// dfmt on

void main()
{
    long N, A, B;
    scan(N, A, B);
    if (B < A)
        swap(A, B);
    if ((B - A) % 2 == 0)
    {
        ((B - A) / 2).writeln();
        return;
    }
    long a = N - A;
    long b = B - 1;
    long c = ((B - A) - 1) / 2 + (A); // 1で折り返す
    long d = (N - (A + N - B + 1)) / 2 + (N - B + 1); // Nで折り返す
    // writeln(a, " ", b, " ", c, " ", d);
    min(a, b, c, d).writeln();
}
