Check if Numbers Are Ascending in a Sentence - Problem

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

int isNumber(char* token) {
    for (int i = 0; token[i]; i++) {
        if (!isdigit(token[i])) return 0;
    }
    return strlen(token) > 0;
}

int solution(char* s) {
    char* copy = malloc(strlen(s) + 1);
    strcpy(copy, s);
    
    int numbers[1000];
    int count = 0;
    
    char* token = strtok(copy, " ");
    while (token != NULL) {
        if (isNumber(token)) {
            numbers[count++] = atoi(token);
        }
        token = strtok(NULL, " ");
    }
    
    for (int i = 1; i < count; i++) {
        if (numbers[i] <= numbers[i-1]) {
            free(copy);
            return 0;
        }
    }
    
    free(copy);
    return 1;
}

int main() {
    char s[10001];
    fgets(s, sizeof(s), stdin);
    s[strcspn(s, "\n")] = 0;
    
    int result = solution(s);
    printf(result ? "true\n" : "false\n");
    return 0;
}