#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <ctype.h>
#include <time.h>
#pragma warning(disable:4996 6031)
void *lowerbound(void *key, void *base, size_t count, size_t itemsize, int(*compare)(const void *, const void *)){
    size_t lo = 0, hi = count - 1, mid = 0;
    if(compare(key, (char *)base + hi * itemsize) > 0){
        return (char *)base + count * itemsize;
    }
    char *pmid = 0;
    while(lo < hi){
        mid = (lo + hi) >> 1;
        pmid = ((char *)base) + mid * itemsize;
        if(compare(pmid, key) < 0){
            lo = mid + 1;
        }
        else{
            hi = mid;
        }
    }
    return (char *)base + lo * itemsize;
}
void *upperbound(void *key, void *base, size_t count, size_t itemsize, int(*compare)(const void *, const void *)){
    size_t lo = 0, hi = count - 1, mid;
    if(compare(key, (char *)base + hi * itemsize) >= 0){
        return (char *)base + count * itemsize;
    }
    char *pmid = 0;
    while(lo < hi){
        mid = (lo + hi) >> 1;
        char *pmid = ((char *)base) + mid * itemsize;
        if(compare(pmid, key) <= 0){
            lo = mid + 1;
        }
        else{
            hi = mid;
        }
    }
    return (char *)base + lo * itemsize;
}
int arr[1919810] = { 0 };
int compare_s32(const void *p, const void *q){
    int x = *((int *)p), y = *((int *)q);
    if(x < y){
        return -1;
    }
    else if(x > y){
        return 1;
    }
    else{
        return 0;
    }
}
int main(){
    int n, t, i, k, *lb, *ub;
    scanf("%d%d", &n, &t);
    for(i = 0; i < n; i++){
        scanf("%d", arr + i);
    }
    while(t--){
        scanf("%d", &k);
        lb = lowerbound(&k, arr, n, sizeof(int), compare_s32);
        ub = upperbound(&k, arr, n, sizeof(int), compare_s32);
        if(*lb == k && (lb < arr + n)){
            printf("%d %d\n", lb - arr + 1, ub - lb);
        }
        else{
            puts("-1");
        }
    }
    return 0;
}