void triplete (int a,int b,int c)
{
    int i,j,k,nr=0;
    for(i=a;i<=b;i++)
        for(j=a;j<=b;++j)
        for(k=a;k<=b;++k)
        if(i<=j && j<=k && i+j+k==c)
    {
        ++nr;
        cout<<"{"<<i<<','<<j<<','<<k<<'}'<<'\n';
    }
    if(nr==0)
        cout<<"nu exista";
}