Cod sursa(job #36495)
Utilizator | Data | 23 martie 2007 17:05:28 | |
---|---|---|---|
Problema | Fractii | Scor | 10 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.31 kb |
#include<fstream.h>
ifstream f("fractii.in");
ofstream g("fractii.out");
long long cm(long a,long b)
{while(b)
{long r=a%b; a=b; b=r;}
return a;
}
int main()
{long long n;
f>>n;
long long t=0;
for(long long i=3;i<=n;i++)
for(long long j=2;j<i;j++)
if(cm(i,j)==1) t++;
g<<1+2*(n-1+t);
return 0;
}