#include<bits/stdc++.h>
using namespace std;
int main(){
    int T;cin>>T;
    while(T--){
        int a,b,R;cin>>a>>b>>R;
        a=abs(a),b=abs(b);
        if(!a){cout<<b*1ll*R<<'\n';continue;}
        int l=0,r=R;
        long long ans=0;
        while(l<r){
            int mid=l+r+1>>1;
            long long w=mid*1ll*b/a;
            if(w<=R&&mid*1ll*mid+w*w<=R*1ll*R) l=mid;
            else r=mid-1;
        }
        for(int i=l-100000;i<=l+100000;i++)if(i>=0&&i<=R){
            int z=sqrtl(R*1ll*R-i*1ll*i);
            ans=max(ans,i*1ll*a+z*1ll*b);
        }
        cout<<ans<<'\n';
    }
}