secventeneuniforme

#include <fstream>
using namespace std;
ifstream f("secventeneuniforme.in");
ofstream g("secventeneuniforme.out");

int main()
{
    int x,y,z,LC=2,LM=0;
    f>>x>>y;
    while(f>>z)
    {
        if(x==y||x==z||y==z)
        {
            if(LC>LM)
                LM=LC;
            LC=2;
        }
        else
            ++LC;
        x=y,y=z;
    }
    if(LC>LM)
        LM=LC;
    g<<LM;
    return 0;
}