#include <bits/stdc++.h> using namespace std; int main(){ double i[3]; cin>>i[0]>>i[1]>>i[2]; sort(i,i+3); if(i[0]*i[0]+i[1]*i[1]==i[2]*i[2])printf("%.1f",i[0]*i[1]/2); else cout<<"No"; return 0; } /************************************************************** Problem: 1047 User: zhouhongyi Language: C++ Result: Accepted Time:10 ms Memory:2076 kb ****************************************************************/