#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define rep(i,n) for(int (i)=0;(i)<(int)(n);++(i)) #define rer(i,l,u) for(int (i)=(int)(l);(i)<=(int)(u);++(i)) #define reu(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i)) #if defined(_MSC_VER) || __cplusplus > 199711L #define aut(r,v) auto r = (v) #else #define aut(r,v) __typeof(v) r = (v) #endif #define each(it,o) for(aut(it, (o).begin()); it != (o).end(); ++ it) #define all(o) (o).begin(), (o).end() #define pb(x) push_back(x) #define mp(x,y) make_pair((x),(y)) #define mset(m,v) memset(m,v,sizeof(m)) #define INF 0x3f3f3f3f #define INFL 0x3f3f3f3f3f3f3f3fLL using namespace std; typedef vector vi; typedef pair pii; typedef vector > vpii; typedef long long ll; template inline void amin(T &x, U y) { if(y < x) x = y; } template inline void amax(T &x, U y) { if(x < y) x = y; } int main() { int n, m; while(cin >> n >> m) { string S, T; cin >> S >> T; vector dp(n+1, vi(m+1, INF)); dp[0][0] = 0; rer(i, 0, n) rer(j, 0, m) { int x = dp[i][j]; if(i+1 < n) amin(dp[i+1][j], x + 1); if(j+1 < m) amin(dp[i][j+1], x + 1); if(i+1 < n && j+1 < m) amin(dp[i+1][j+1], x + (S[i] != T[j])); } int ans = dp[n][m]; cout << ans << endl; } return 0; }