Zencryption

#include<stdio.h>
#include<string.h>

int main()
{
    int k;
    scanf("%d",&k);
    char input[1010];
    scanf("%s",input);
    if(k == 1){
        printf("%s",input);
        return 0;
    }
    int len = strlen(input);
    if(k >= len){
        for(int i=len-1;i>=0;i--){
            printf("%c",input[i]);
        }
        return 0;
    }
    char ans[1010];for(int i=0;i<1010;i++)ans[i] = '\0';
    int indextop = k-1;
    int indexinput = 0;
    while(indextop < len){
        for(int i=0;i<k;i++){
            if(indextop + i < len)ans[indextop + i] = input[indexinput++];
        }
        indextop += (4*(k-1));// + (k-2))
    }
    for(int i = 1 ; i <= k - 2 ; i ++){
        int indexmid = k - i - 1;
        int cnt = 0;
        while(indexmid < len){
            ans[indexmid] = input[indexinput++];
            cnt++;
            if(cnt % 2 == 1){ //odd
                indexmid += k + (2 * (i - 1) ) + 1;
            }
            else{ //even
                indexmid += k + (2 * (k - 2 - i) ) + 1;
            }
        }
    }
    int i = 0;
    while(indexinput < len){
        while(ans[i] != '\0')i++;
        if(i < len)ans[i] = input[indexinput++];
    }
    printf("%s",ans);
    return 0;
}