doce_do_dias_das_bruxas.cpp

//
//  halloween.cpp
//
//  Created by Lucca Siaudzionis on 03/03/15.
//
//  URI 1656 - Doces do Dia das Bruxas
 
#include <cstdio>
 
//------------------
#define MAXN 100100
 
int c, n;
int resto[MAXN];
int candy[MAXN];
//------------------
 
int main(){
     
    while(scanf("%d %d", &c, &n) && n){
         
        for(int i = 1;i <= n;i++){
            scanf("%d", &candy[i]);
            candy[i] %= c;
        }
         
        for(int i = 1;i <= c;i++) resto[i] = -1;
         
        int sum = 0;
        resto[0] = 0;
        for(int i = 1;i <= c;i++){
             
            sum += candy[i];
            sum %= c;
             
            if(resto[sum] != -1){
                printf("%d", resto[sum]+1);
                for(int j = resto[sum]+2;j <= i;j++) printf(" %d", j);
                printf("\n");
                break;
            }
             
            resto[sum] = i;
        }
         
    }
     
    return 0;
}