#include <stdio.h>
#define MAXN 26

FILE * input = fopen("nthword.in","r");
FILE * output = fopen("nthword.out","w");

int N,K,L, current;
char letters[MAXN], word[MAXN];

void build(int depth, int last){
    if(N == current) return;
    if (depth == K){
        //printf("%s\n", word);
        if ( word[0] == word[K-1] ) return;
        if (++current == N)
            fprintf(output,"%s\n", word);
        return;
    }
    for (int i=last;i<L;i++){
        word[depth] = letters[i];
        build( depth+1, i);
    }
}

int main(){
    fscanf( input, "%s", &letters);
    fscanf( input, "%d %d", &K, &N);
    //printf("%s\n", letters);
    for (int i=0;i<MAXN;i++){
        if( letters[i] == 0){
            L = i;
            break;
        }
    }
    current=0;
    build(0,0);
    return 0;
}
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