#include<iostream> #include<cmath> usingnamespace std; typedeflonglong ll; ll n,m; ll f(ll x){ ll res = 0; ll t = sqrt((double)x); for (ll i = 1; i <= t; i ++) res += x /i; res = res *2 - (ll)t*t; return res; }
#include<iostream> #include<algorithm> #include<map> #include<unordered_map> usingnamespace std; constint N = 1e6 + 7; map<char,int> q; int a[4][4]; int n,m; char s[N],e[N]; intmain(){ q['A'] = 0,q['G'] = 1,q['C'] = 2, q['T'] = 3; scanf("%s%s",s,e); for (int i = 0; s[i]; i ++) if (s[i] != e[i]) a[q[s[i]]][q[e[i]]]++; int res = 0; for (int i = 0; i < 4; i++) for (int j = 0; j< 4; j++){ int x = min(a[i][j],a[j][i]); a[i][j] -= x, a[j][i] -=x; res += x; } for (int i =0 ; i < 4; i++) for (int j = 0; j < 4; j++) for (int k = 0; k< 4; k++){ int x = min(min(a[i][j],a[j][k]),a[k][i]); a[i][j] -= x, a[j][k] -= x, a[k][i] -= x; res += x << 1; } for (int i = 0; i < 4; i++) res += (a[i][0] * 3); printf("%d\n",res); }