UVA 10791 Minimum Sum LCM

#include<cstdio>
#include<cmath>
#include<vector>
using namespace std;
#define ll long long
#define pir pair<ll,ll>
vector<pir> f;ll n,cas; 
void deal(ll x){
    f.clear();
    ll m=floor(sqrt(x)+0.5);
    for(ll i=2;i<=m;i++){
        if(x%i) continue;
        ll q=0;
        while(x%i==0) q++,x/=i;
        f.push_back(make_pair(i,q)); 
    }
    if(x>1) f.push_back(make_pair(x,1));
}
ll fpow(ll a,ll p){
    ll res=1;
    for(;p;p>>=1,a=a*a) if(p&1) res=res*a;
    return res;
}
void out(){
    ll ans=0,size=f.size();
    for(ll i=0;i<size;i++) ans+=fpow(f[i].first,f[i].second);
    if(size==1) ans++;
    printf("Case %lld: ",++cas);
    printf("%lld\n",ans);
}
int main(){
    while(~scanf("%lld",&n)){
        if(!n) break;
        if(n==1) {printf("Case %lld: 2\n",++cas);continue;}
        deal(n);out();
    } 
    return 0;
}