sicily 1007. To and Fro

#include<iostream>
#include<stdio.h>
using namespace std;
int main()
{
    int column,row,length,i,time;
    char ch,list[100][20];
    
    while(scanf("%d",&column),column)
    {
        scanf("\n");
        length=i=0;
        while(scanf("%c",&ch),ch!='\n')
        {
            length++;
            list[(length-1)/column][i++]=ch;
            i=i%column;
        }
        row=length/column;
        for(time=0;time<column;time++)
            for(i=0;i<row;i++)
                if(i%2)
                    cout<<list[i][column-time-1];
                else 
                    cout<<list[i][time];
        printf("\n");
    }    
    return 0;
}