#include int main(void){ int N; // number of words. N <= (10^5) int A[100000]; // boxes(each number). A[i] <= (10^9) int same = 0; // number of same words int count = 0; // scanf("%d",&N); for(int i = 0;i < N;i++){ scanf("%d",&A[i]); } count = N; // printf("%d",A[0]); // check OK for(int j = 0;j < N;j++){ for(int k = 0;k < N;k++){ if(k == j){ continue; } else if(A[j] == A[k]){ same += 1; } count -= same; same = 0; } } printf("%d\n",count); return 0; }