P1446 [HNOI2008]Cards

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
using namespace std;

const int N=65;

int Sr,Sb,Sg,m,p;
int fac[N],ifac[N];

int ksm(int x,int k)
{
    int res=1;
    while(k)
    {
        if(k&1)
            res=1ll*res*x%p;
        k>>=1;
        x=1ll*x*x%p;
    }
    return res;
}

int main()
{
    scanf("%d%d%d%d%d",&Sr,&Sb,&Sg,&m,&p);
    int lim=Sr+Sb+Sg;
    fac[0]=1;
    for(int i=1;i<=lim;++i)
        fac[i]=fac[i-1]*i%p;
    ifac[lim]=ksm(fac[lim],p-2);
    for(int i=lim-1;~i;--i)
        ifac[i]=ifac[i+1]*(i+1)%p;
    cout<<1ll*fac[lim]*ifac[Sr]%p*ifac[Sb]%p*ifac[Sg]%p*ksm(m+1,p-2)%p;
    return 0;
}