C++ :

#include <cstdio>
int main(){
    int a;
    if(scanf("%d", &a) != 1) return 0;
    if(a % 9 != 0){ puts("No answer"); return 0; }
    int d = a / 9;
    int first = 1;
    for(int x = 1; x <= 9; x++){
        int y = x - d;
        if(y < 0 || y > 9) continue;
        if(!first) putchar(' ');
        printf("%d", x * 10 + y);
        first = 0;
    }
    if(first) puts("No answer"); else putchar('\n');
    return 0;
}