#include <bits/stdc++.h> using namespace std; int main(){ int i,sum=0; cin>>i; for(int i1=1;i1<=i;i1++){ for(int i2=1;i2<i1;i2++){ if((i1+i2)%7==0||(i1+i2)%3==0)sum++; } } cout<<sum; return 0; } /************************************************************** Problem: 1086 User: zhouhongyi Language: C++ Result: Accepted Time:7 ms Memory:2072 kb ****************************************************************/