import std.stdio, std.algorithm, std.string, std.conv, std.array, std.range, std.math;
int read() { return readln.chomp.to!int; }
int[] reads() { return readln.split.to!(int[]); }

string solve(string s) {
    int w = read();
    string r;
    foreach (i, c; s) if (i % w == 0) r ~= c;
    return r;
}

void main() {
    writeln(readln.chomp.solve);
}
