Dominant Army

In the medieval age, there were $3$ kingdoms $A$, $B$, and $C$. The army of these kingdom had $N_A$, $N_B$, and $N_C$ soldiers respectively. You are given that an army with $X$ soldiers can defeat an army with $Y$ soldiers only if $X \gt Y$. An army is said to be **dominant** if it can defeat both the other armies **combined**. For example, kingdom $C$'s army will be dominant only if $N_C > N_