#pragma GCC optimize("Ofast") #pragma GCC optimize("unroll-loops") #pragma GCC optimize("inline") #include using namespace std; #define MD (1000000007U) void*wmem; char memarr[96000000]; template inline void walloc1d(T **arr, int x, void **mem = &wmem){ static int skip[16] = {0, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1}; (*mem) = (void*)( ((char*)(*mem)) + skip[((unsigned long long)(*mem)) & 15] ); (*arr)=(T*)(*mem); (*mem)=((*arr)+x); } template inline void walloc1d(T **arr, int x1, int x2, void **mem = &wmem){ walloc1d(arr, x2-x1, mem); (*arr) -= x1; } struct Modint{ unsigned val; Modint(){ val=0; } Modint(int a){ val = ord(a); } Modint(unsigned a){ val = ord(a); } Modint(long long a){ val = ord(a); } Modint(unsigned long long a){ val = ord(a); } inline unsigned ord(unsigned a){ return a%MD; } inline unsigned ord(int a){ a %= (int)MD; if(a < 0){ a += MD; } return a; } inline unsigned ord(unsigned long long a){ return a%MD; } inline unsigned ord(long long a){ a %= (int)MD; if(a < 0){ a += MD; } return a; } inline unsigned get(){ return val; } inline Modint &operator++(){ val++; if(val >= MD){ val -= MD; } return *this; } inline Modint &operator--(){ if(val == 0){ val = MD - 1; } else{ --val; } return *this; } inline Modint operator++(int a){ Modint res(*this); val++; if(val >= MD){ val -= MD; } return res; } inline Modint operator--(int a){ Modint res(*this); if(val == 0){ val = MD - 1; } else{ --val; } return res; } inline Modint &operator+=(Modint a){ val += a.val; if(val >= MD){ val -= MD; } return *this; } inline Modint &operator-=(Modint a){ if(val < a.val){ val = val + MD - a.val; } else{ val -= a.val; } return *this; } inline Modint &operator*=(Modint a){ val = ((unsigned long long)val*a.val)%MD; return *this; } inline Modint &operator/=(Modint a){ return *this *= a.inverse(); } inline Modint operator+(Modint a){ return Modint(*this)+=a; } inline Modint operator-(Modint a){ return Modint(*this)-=a; } inline Modint operator*(Modint a){ return Modint(*this)*=a; } inline Modint operator/(Modint a){ return Modint(*this)/=a; } inline Modint operator+(int a){ return Modint(*this)+=Modint(a); } inline Modint operator-(int a){ return Modint(*this)-=Modint(a); } inline Modint operator*(int a){ return Modint(*this)*=Modint(a); } inline Modint operator/(int a){ return Modint(*this)/=Modint(a); } inline Modint operator+(long long a){ return Modint(*this)+=Modint(a); } inline Modint operator-(long long a){ return Modint(*this)-=Modint(a); } inline Modint operator*(long long a){ return Modint(*this)*=Modint(a); } inline Modint operator/(long long a){ return Modint(*this)/=Modint(a); } inline Modint operator-(void){ Modint res; if(val){ res.val=MD-val; } else{ res.val=0; } return res; } inline operator bool(void){ return val!=0; } inline operator int(void){ return get(); } inline operator long long(void){ return get(); } inline Modint inverse(){ int a = val; int b = MD; int u = 1; int v = 0; int t; Modint res; while(b){ t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } if(u < 0){ u += MD; } res.val = u; return res; } inline Modint pw(unsigned long long b){ Modint a(*this); Modint res; res.val = 1; while(b){ if(b&1){ res *= a; } b >>= 1; a *= a; } return res; } inline bool operator==(int a){ return ord(a)==val; } inline bool operator!=(int a){ return ord(a)!=val; } } ; inline Modint operator+(int a, Modint b){ return Modint(a)+=b; } inline Modint operator-(int a, Modint b){ return Modint(a)-=b; } inline Modint operator*(int a, Modint b){ return Modint(a)*=b; } inline Modint operator/(int a, Modint b){ return Modint(a)/=b; } inline Modint operator+(long long a, Modint b){ return Modint(a)+=b; } inline Modint operator-(long long a, Modint b){ return Modint(a)-=b; } inline Modint operator*(long long a, Modint b){ return Modint(a)*=b; } inline Modint operator/(long long a, Modint b){ return Modint(a)/=b; } inline void my_putchar_unlocked(const int k){ putchar_unlocked(k); } inline void wt_L(char a){ my_putchar_unlocked(a); } inline void wt_L(int x){ int s=0; int m=0; char f[10]; if(x<0){ m=1; x=-x; } while(x){ f[s++]=x%10; x/=10; } if(!s){ f[s++]=0; } if(m){ my_putchar_unlocked('-'); } while(s--){ my_putchar_unlocked(f[s]+'0'); } } inline void wt_L(unsigned x){ int s=0; char f[10]; while(x){ f[s++]=x%10; x/=10; } if(!s){ f[s++]=0; } while(s--){ my_putchar_unlocked(f[s]+'0'); } } inline void wt_L(long long x){ int s=0; int m=0; char f[20]; if(x<0){ m=1; x=-x; } while(x){ f[s++]=x%10; x/=10; } if(!s){ f[s++]=0; } if(m){ my_putchar_unlocked('-'); } while(s--){ my_putchar_unlocked(f[s]+'0'); } } inline void wt_L(unsigned long long x){ int s=0; char f[21]; while(x){ f[s++]=x%10; x/=10; } if(!s){ f[s++]=0; } while(s--){ my_putchar_unlocked(f[s]+'0'); } } inline void wt_L(Modint x){ int i; i = (int)x; wt_L(i); } int WRITER_DOUBLE_DIGIT = 15; inline int writerDigit_double(){ return WRITER_DOUBLE_DIGIT; } inline void writerDigit_double(int d){ WRITER_DOUBLE_DIGIT = d; } inline void wt_L(double x){ const int d = WRITER_DOUBLE_DIGIT; int k; int r; double v; if(x!=x || (x==x+1 && x==2*x)){ my_putchar_unlocked('E'); my_putchar_unlocked('r'); my_putchar_unlocked('r'); return; } if(x < 0){ my_putchar_unlocked('-'); x = -x; } x += 0.5 * pow(0.1, d); r = 0; v = 1; while(x >= 10*v){ v *= 10; r++; } while(r >= 0){ r--; k = floor(x / v); if(k >= 10){ k = 9; } if(k <= -1){ k = 0; } x -= k * v; v *= 0.1; my_putchar_unlocked(k + '0'); } if(d > 0){ my_putchar_unlocked('.'); v = 1; for(r=(0);r<(d);r++){ v *= 0.1; k = floor(x / v); if(k >= 10){ k = 9; } if(k <= -1){ k = 0; } x -= k * v; my_putchar_unlocked(k + '0'); } } } inline void wt_L(const char c[]){ int i=0; for(i=0;c[i]!='\0';i++){ my_putchar_unlocked(c[i]); } } inline void wt_L(string &x){ int i=0; for(i=0;x[i]!='\0';i++){ my_putchar_unlocked(x[i]); } } template inline S chmax(S &a, T b){ if(a struct Comb{ int mem_fact; T*factri; T*ifactri; int mem_dfact; T*dfactri; int mem_pw2; int mem_pw3; int mem_pw10; int mem_rep1; T*pw2c; T*pw3c; T*pw10c; T*rep1c; int mem_ipw2; int mem_ipw3; int mem_ipw10; T*ipw2c; T*ipw3c; T*ipw10c; Comb(){ mem_fact = 0; mem_dfact = 0; mem_pw2 = mem_pw3 = mem_pw10 = mem_rep1 = 0; mem_ipw2 = mem_ipw3 = mem_ipw10 = 0; } inline void expand_fact(int k){ int i; if(k <= mem_fact){ return; } chmax(k, 2 * mem_fact); if(mem_fact == 0){ factri = (T*)malloc(k * sizeof(T)); ifactri = (T*)malloc(k * sizeof(T)); factri[0] = 1; for(i=(1);i<(k);i++){ factri[i] = i * factri[i-1]; } ifactri[k-1] = 1 / factri[k-1]; for(i=(k-1)-1;i>=(0);i--){ ifactri[i] = (i+1) * ifactri[i+1]; } } else{ factri = (T*)realloc(factri, k * sizeof(T)); ifactri = (T*)realloc(ifactri, k * sizeof(T)); for(i=(mem_fact);i<(k);i++){ factri[i] = i * factri[i-1]; } ifactri[k-1] = 1 / factri[k-1]; for(i=(k-1)-1;i>=(mem_fact);i--){ ifactri[i] = (i+1) * ifactri[i+1]; } } mem_fact = k; } inline T fac(int k){ if(mem_fact < k+1){ expand_fact(k+1); } return factri[k]; } inline T ifac(int k){ if(mem_fact < k+1){ expand_fact(k+1); } return ifactri[k]; } inline T C(int a, int b){ if(b < 0 || b > a){ return 0; } if(mem_fact < a+1){ expand_fact(a+1); } return factri[a] * ifactri[b] * ifactri[a-b]; } inline T P(int a, int b){ if(b < 0 || b > a){ return 0; } if(mem_fact < a+1){ expand_fact(a+1); } return factri[a] * ifactri[a-b]; } inline T H(int a, int b){ if(a==0 && b==0){ return 1; } if(a <= 0 || b < 0){ return 0; } if(mem_fact < a+b){ expand_fact(a+b); } return C(a+b-1, b); } inline T Multinomial(int sz, int a[]){ int i; int s = 0; T res; for(i=(0);i<(sz);i++){ s += a[i]; } if(mem_fact < s+1){ expand_fact(s+1); } res = factri[s]; for(i=(0);i<(sz);i++){ res *= ifactri[a[i]]; } return res; } inline T Multinomial(int a){ return 1; } inline T Multinomial(int a, int b){ if(mem_fact < a+b+1){ expand_fact(a+b+1); } return factri[a+b] * ifactri[a] * ifactri[b]; } inline T Multinomial(int a, int b, int c){ if(mem_fact < a+b+c+1){ expand_fact(a+b+c+1); } return factri[a+b+c] * ifactri[a] * ifactri[b] * ifactri[c]; } inline T Multinomial(int a, int b, int c, int d){ if(mem_fact < a+b+c+d+1){ expand_fact(a+b+c+d+1); } return factri[a+b+c+d] * ifactri[a] * ifactri[b] * ifactri[c] * ifactri[d]; } inline T Catalan(int n){ if(n < 0){ return 0; } if(mem_fact < 2*n+1){ expand_fact(2*n+1); } return factri[2*n] * ifactri[n] * ifactri[n+1]; } inline T Catalan(int n, int m, int k){ if(k <= 0){ return C(n+m, n); } if(n < k || m < k){ return 0; } return C(n+m, m) - C(n+m, k-1); } inline T Catalan_s(long long n, long long m, long long k){ if(k <= 0){ return C_s(n+m, n); } if(n < k || m < k){ return 0; } return C_s(n+m, m) - C_s(n+m, k-1); } inline T C_s(long long a, long long b){ long long i; T res; if(b < 0 || b > a){ return 0; } if(b > a - b){ b = a - b; } res = 1; for(i=(0);i<(b);i++){ res *= a - i; res /= i + 1; } return res; } inline T P_s(long long a, long long b){ long long i; T res; if(b < 0 || b > a){ return 0; } res = 1; for(i=(0);i<(b);i++){ res *= a - i; } return res; } inline T H_s(long long a, long long b){ if(a==0 && b==0){ return 1; } if(a <= 0 || b < 0){ return 0; } return C_s(a+b-1, b); } inline T per_s(long long n, long long k){ T d; int m; if(n < 0 || k < 0){ return 0; } if(n == k && k == 0){ return 1; } if(n == 0 || k == 0){ return 0; } if(k==1){ return 1; } if(k==2){ d = n / 2; return d; } if(k==3){ d = (n-1) / 6; m = (n-1) % 6; if(m==0){ return 3 * d * d + d; } if(m==1){ return 3 * d * d + 2 * d; } if(m==2){ return 3 * d * d + 3 * d + 1; } if(m==3){ return 3 * d * d + 4 * d + 1; } if(m==4){ return 3 * d * d + 5 * d + 2; } if(m==5){ return 3 * d * d + 6 * d + 3; } } assert(0 && "per_s should be k <= 3"); return -1; } inline void expand_dfact(int k){ int i; if(k <= mem_dfact){ return; } chmax(k, 3); chmax(k, 2 * mem_dfact); if(mem_dfact==0){ dfactri = (T*)malloc(k * sizeof(T)); dfactri[0] = dfactri[1] = 1; for(i=(2);i<(k);i++){ dfactri[i] = i * dfactri[i-2]; } } else{ dfactri = (T*)realloc(dfactri, k * sizeof(T)); for(i=(mem_dfact);i<(k);i++){ dfactri[i] = i * dfactri[i-2]; } } mem_dfact = k; } inline void expand_pw2(int k){ int i; if(k <= mem_pw2){ return; } chmax(k, 2 * mem_pw2); if(mem_pw2==0){ pw2c = (T*)malloc(k * sizeof(T)); pw2c[0] = 1; for(i=(1);i<(k);i++){ pw2c[i] = 2 * pw2c[i-1]; } } else{ pw2c = (T*)realloc(pw2c, k * sizeof(T)); for(i=(mem_pw2);i<(k);i++){ pw2c[i] = 2 * pw2c[i-1]; } } mem_pw2 = k; } inline void expand_ipw2(int k){ int i; if(k <= mem_ipw2){ return; } chmax(k, 2); chmax(k, 2 * mem_ipw2); if(mem_ipw2==0){ ipw2c = (T*)malloc(k * sizeof(T)); ipw2c[0] = 1; ipw2c[1] = ipw2c[0] / 2; for(i=(1);i<(k);i++){ ipw2c[i] = ipw2c[1] * ipw2c[i-1]; } } else{ ipw2c = (T*)realloc(ipw2c, k * sizeof(T)); for(i=(mem_ipw2);i<(k);i++){ ipw2c[i] = ipw2c[1] * ipw2c[i-1]; } } mem_ipw2 = k; } inline void expand_pw3(int k){ int i; if(k <= mem_pw3){ return; } chmax(k, 2 * mem_pw3); if(mem_pw3==0){ pw3c = (T*)malloc(k * sizeof(T)); pw3c[0] = 1; for(i=(1);i<(k);i++){ pw3c[i] = 3 * pw3c[i-1]; } } else{ pw3c = (T*)realloc(pw3c, k * sizeof(T)); for(i=(mem_pw3);i<(k);i++){ pw3c[i] = 3 * pw3c[i-1]; } } mem_pw3 = k; } inline void expand_ipw3(int k){ int i; if(k <= mem_ipw3){ return; } chmax(k, 2); chmax(k, 2 * mem_ipw3); if(mem_ipw3==0){ ipw3c = (T*)malloc(k * sizeof(T)); ipw3c[0] = 1; ipw3c[1] = ipw3c[0] / 3; for(i=(1);i<(k);i++){ ipw3c[i] = ipw3c[1] * ipw3c[i-1]; } } else{ ipw3c = (T*)realloc(ipw3c, k * sizeof(T)); for(i=(mem_ipw3);i<(k);i++){ ipw3c[i] = ipw3c[1] * ipw3c[i-1]; } } mem_ipw3 = k; } inline void expand_pw10(int k){ int i; if(k <= mem_pw10){ return; } chmax(k, 2 * mem_pw10); if(mem_pw10==0){ pw10c = (T*)malloc(k * sizeof(T)); pw10c[0] = 1; for(i=(1);i<(k);i++){ pw10c[i] = 10 * pw10c[i-1]; } } else{ pw10c = (T*)realloc(pw10c, k * sizeof(T)); for(i=(mem_pw10);i<(k);i++){ pw10c[i] = 10 * pw10c[i-1]; } } mem_pw10 = k; } inline void expand_ipw10(int k){ int i; if(k <= mem_ipw10){ return; } chmax(k, 2); chmax(k, 2 * mem_ipw10); if(mem_ipw10==0){ ipw10c = (T*)malloc(k * sizeof(T)); ipw10c[0] = 1; ipw10c[1] = ipw10c[0] / 10; for(i=(1);i<(k);i++){ ipw10c[i] = ipw10c[1] * ipw10c[i-1]; } } else{ ipw10c = (T*)realloc(ipw10c, k * sizeof(T)); for(i=(mem_ipw10);i<(k);i++){ ipw10c[i] = ipw10c[1] * ipw10c[i-1]; } } mem_ipw10 = k; } inline void expand_rep1(int k){ int i; if(k <= mem_rep1){ return; } chmax(k, 2 * mem_rep1); if(mem_rep1==0){ rep1c = (T*)malloc(k * sizeof(T)); rep1c[0] = 0; for(i=(1);i<(k);i++){ rep1c[i] = 10 * rep1c[i-1] + 1; } } else{ rep1c = (T*)realloc(rep1c, k * sizeof(T)); for(i=(mem_rep1);i<(k);i++){ rep1c[i] = 10 * rep1c[i-1] + 1; } } mem_rep1 = k; } inline T dfac(int k){ if(k >= 0){ if(mem_dfact < k+1){ expand_dfact(k+1); } return dfactri[k]; } if(k==-1){ return 1; } k = - k - 2; if(k % 4 == 1){ return 1 / (-dfac(k)); } return 1 / dfac(k); } inline T pw2(int k){ if(k >= 0){ if(mem_pw2 < k+1){ expand_pw2(k+1); } return pw2c[k]; } else{ k = -k; if(mem_ipw2 < k+1){ expand_ipw2(k+1); } return ipw2c[k]; } } inline T pw3(int k){ if(k >= 0){ if(mem_pw3 < k+1){ expand_pw3(k+1); } return pw3c[k]; } else{ k = -k; if(mem_ipw3 < k+1){ expand_ipw3(k+1); } return ipw3c[k]; } } inline T pw10(int k){ if(k >= 0){ if(mem_pw10 < k+1){ expand_pw10(k+1); } return pw10c[k]; } else{ k = -k; if(mem_ipw10 < k+1){ expand_ipw10(k+1); } return ipw10c[k]; } } inline T repunit(int k){ if(mem_rep1 < k+1){ expand_rep1(k+1); } return rep1c[k]; } } ; template<> inline Modint Comb::C_s(long long a, long long b){ long long i; Modint res; Modint d; if(b < 0 || b > a){ return 0; } if(b > a - b){ b = a - b; } res = d = 1; for(i=(0);i<(b);i++){ res *= a - i; d *= i + 1; } return res / d; } long long llReader(long long mn, long long mx, char nx){ int i; int fg = 0; int m = 1; long long res = 0; double tmp = 0; for(;;){ i = getchar(); if(fg==0 && i=='-'){ fg++; m = -1; } else if('0' <= i && i <= '9'){ fg++; res = 10 * res + i - '0'; tmp = 10 * tmp + i - '0'; assert(tmp < 1e20); } else{ break; } } assert(tmp / 2 <= res); assert((m==1 && fg >= 1) || (m==-1 && fg >= 2)); assert(mn <= m * res && m * res <= mx); assert(i == nx); return m * res; } Comb comb; Modint solve(long long A, long long B, long long C, long long D){ int i; Modint res = 0; if(A != B){ return 0; } if(A==B && B==D && D==0){ return 1; } for(i=(0);i<(A);i++){ res += (i+1) * comb.C(2*A-2-i, A-1-i) / A * comb.H(2*A-i-1, D); } res *= comb.H(A+B+D+1,C); return res; } Modint baka(long long A, long long B, long long C, long long D){ int i; int j; int k; int n = 0; int arr[100]; int sz; int gen[200]; Modint res = 0; for(i=(0);i<(A);i++){ arr[n++] = 0; } for(i=(0);i<(B);i++){ arr[n++] = 1; } for(i=(0);i<(C);i++){ arr[n++] = 2; } for(i=(0);i<(D);i++){ arr[n++] = 3; } do{ sz = 0; for(i=(0);i<(n);i++){ if(arr[i]==0){ gen[sz++] = 1; } if(arr[i]==1){ gen[sz++] = -1; } if(arr[i]==2){ gen[sz++] = 1; gen[sz++] = -1; } if(arr[i]==3){ gen[sz++] = -1; gen[sz++] = 1; } } k = 0; for(i=(0);i<(sz);i++){ k += gen[i]; if(k == -1){ goto tU__gIr_; } } if(k==0){ res++; } tU__gIr_:; } while(next_permutation(arr,arr+n)); return res; } Modint solve2(long long A, long long B, long long C, long long D){ Modint res = 0; if(A != B){ return 0; } if(A==B && B==D && D==0){ return 1; } return comb.C(2*A+D,A-1) * comb.C(A-1+D,A-1) * comb.H(A+B+D+1,C) / A; } int main(){ int jZyWAPpY; wmem = memarr; long long T; long long A; long long B; long long C; long long D; Modint res = 0; T = llReader(1, 100000, '\n'); for(jZyWAPpY=(0);jZyWAPpY<(T);jZyWAPpY++){ A = llReader(0, 100000, ' '); B = llReader(0, 100000, ' '); C = llReader(0, 100000, ' '); D = llReader(0, 100000, '\n'); assert(A+B+C+D >= 1); wt_L(solve2(A,B,C,D)); wt_L('\n'); } assert(getchar() == EOF); return 0; puts(""); for(A=(0);A<(7);A++){ for(B=(0);B<(7);B++){ for(C=(0);C<(7);C++){ for(D=(0);D<(7);D++){ Modint res1; Modint res2; res1 = solve(A,B,C,D); res2 = solve2(A,B,C,D); wt_L(A); wt_L(' '); wt_L(B); wt_L(' '); wt_L(C); wt_L(' '); wt_L(D); wt_L(' '); wt_L(":"); wt_L(' '); wt_L(res1); wt_L(' '); wt_L(res2); wt_L('\n'); assert(res1==res2); } } } } res = solve(A,B,C,D); wt_L(res); wt_L('\n'); return 0; } // cLay version 20210717-1 [beta] // --- original code --- // ll llReader(ll mn, ll mx, char nx){ // int i, fg = 0, m = 1; // ll res = 0; double tmp = 0; // // for(;;){ // i = getchar(); // if(fg==0 && i=='-'){ // fg++; // m = -1; // } else if('0' <= i <= '9'){ // fg++; // res = 10 * res + i - '0'; // tmp = 10 * tmp + i - '0'; // assert(tmp < 1e20); // } else { // break; // } // } // assert(tmp / 2 <= res); // assert((m==1 && fg >= 1) || (m==-1 && fg >= 2)); // assert(mn <= m * res <= mx); // assert(i == nx); // return m * res; // } // // Comb comb; // Modint solve(ll A, ll B, ll C, ll D){ // Modint res = 0; // if(A != B) return 0; // if(A==B==D==0) return 1; // rep(i,A) res += (i+1) * comb.C(2*A-2-i, A-1-i) / A * comb.H(2*A-i-1, D); // res *= comb.H(A+B+D+1,C); // return res; // } // // Modint baka(ll A, ll B, ll C, ll D){ // int i, j, k, n = 0, arr[100], sz, gen[200]; // Modint res = 0; // rep(i,A) arr[n++] = 0; // rep(i,B) arr[n++] = 1; // rep(i,C) arr[n++] = 2; // rep(i,D) arr[n++] = 3; // do{ // sz = 0; // rep(i,n){ // if(arr[i]==0) gen[sz++] = 1; // if(arr[i]==1) gen[sz++] = -1; // if(arr[i]==2) gen[sz++] = 1, gen[sz++] = -1; // if(arr[i]==3) gen[sz++] = -1, gen[sz++] = 1; // } // k = 0; // rep(i,sz){ // k += gen[i]; // if(k == -1) break_continue; // } // if(k==0) res++; // }while(next_permutation(arr,arr+n)); // return res; // } // // Modint solve2(ll A, ll B, ll C, ll D){ // Modint res = 0; // if(A != B) return 0; // if(A==B==D==0) return 1; // return comb.C(2*A+D,A-1) * comb.C(A-1+D,A-1) * comb.H(A+B+D+1,C) / A; // } // // { // ll T, A, B, C, D; // Modint res = 0; // T = llReader(1, 1d5, '\n'); // rep(T){ // A = llReader(0, 1d5, ' '); // B = llReader(0, 1d5, ' '); // C = llReader(0, 1d5, ' '); // D = llReader(0, 1d5, '\n'); // assert(A+B+C+D >= 1); // wt(solve2(A,B,C,D)); // } // assert(getchar() == EOF); // return 0; // // puts(""); // rep(A,7) rep(B,7) rep(C,7) rep(D,7){ // Modint res1, res2; // res1 = solve(A,B,C,D); // res2 = solve2(A,B,C,D); // wt(A,B,C,D,":",res1,res2); // assert(res1==res2); // } // // // res = solve(A,B,C,D); // wt(res); // }