#include <bits/stdc++.h>
using namespace std;
long double coeff[7] = {0,0,0,0,0,0,0};
int six_C_i[] = {1,6,15,20,15,6,1};
long long po25[] = {1,0,0,0,0,0,0};
long long po26[] = {1,0,0,0,0,0,0};
unordered_map<long long,int>dp;
int exp(int N)
{
if(N < 2) return 0;
if(dp.find(N)!=dp.end()) return dp[N];
int res = 1;
for(int i=0;i<7;i++)
{
res+=exp((int)(N * coeff[i]));
}
return dp[N] = res;
}
int main()
{
for(int i=1;i<7;i++)
{
po25[i] = po25[i-1]*25;
po26[i] = po26[i-1]*26;
}
for(int i=0;i<7;i++)
{
coeff[i] = six_C_i[i] * (1.00*po25[6-i] / po26[6]);
coeff[i]/=7;
}
int N = po26[6];
cout << exp(N) << endl;
return 0;
}
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