#include int x = 0; void search(int left, int right, int sum, int sum2, int *a) { if(x) return; int i; for( i = left; i < right; i++){ if( sum == sum2 + a[i])x = 1; if( sum > sum2 + a[i]) { search(i+1, right, sum, sum2 + a[i], a); } } } int main(void) { int n, a[101], i, sum = 0; scanf("%d", &n); for( i = 0; i < n; i++) { scanf("%d", &a[i]); sum += a[i]; } if( sum%2 ) { printf("impossible\n"); return 0; } search(0, n-1, sum/2, 0, a); (x)? printf("possible\n") : printf("impossible\n"); return 0; }