import std.algorithm;
import std.array;
import std.conv;
import std.math;
import std.range;
import std.stdio;
import std.string;
import std.typecons;

int readint() {
    return readln.chomp.to!int;
}

int[] readints() {
    return readln.split.map!(to!int).array;
}

void main() {
    int k;
    while ((k = readint) != 0) {
        auto xs = readints;
        writeln(xs.sum / (k - 1));
    }
}