#include<iostream>#include<cstring>#include<string>using namespace std;const int SIZE=10000;const int LENGTH=10;int n,m,a[SIZE][LENGTH];int h(int u,int v){ int ans,i; ans=0; for(i=1;i<=n;i++) if( a[u][i]!=a[v][i]) ans++; return ans;}int main(){ int sum,i,j; cin>>n; memset(a,0,sizeof(a)); m=1; while(1) { i=1; while( (i<=n) && (a[m][i]==1) ) i++; if(i>n) break; m++; a[m][i]=1; for(j=i+1;j<=n;j++) a[m][j]=a[m-1][j]; } sum=0; for(i=1;i<=m;i++) for(j=1;j<=m;j++) sum+=h(i,j); cout<<sum<<endl; return 0;}输入：7 输出：_________