#include <stdio.h>
int find_missing(int n, int a[]) {
int min = 0;
min = a[0];
int N = sizeof(a) / sizeof(a[0]);
for (int i = 0; i < N; i++) {
if (a[i] < min) {
min = a[i];
}
}
int max = a[0];
for (int i = 0; i < N; i++) {
if (a[i] > max) {
max = a[i];
}
}
int num = 0;
for (int q = min; q < max; q++) {
num = 0;
for (int i = 0; i < N; i++) {
if (a[i] == q) {
num++;
}
}
if (num != N) {
return q;
}
}
}
int main() {
int a[5] = {1, 2, 3, 5, 6};
printf("%d", int find_missing(int n, int a[])) return 0;
}