#include <stdio.h>
#include <stdlib.h>
#define N 512
int main() {
    double **A=malloc(N*sizeof(double*)),**B=malloc(N*sizeof(double*)),**C=malloc(N*sizeof(double*));
    for(int i=0;i<N;i++){A[i]=malloc(N*sizeof(double));B[i]=malloc(N*sizeof(double));C[i]=malloc(N*sizeof(double));
    for(int j=0;j<N;j++){A[i][j]=(double)rand()/RAND_MAX;B[i][j]=(double)rand()/RAND_MAX;C[i][j]=0;}}
    for(int i=0;i<N;i++)for(int j=0;j<N;j++)for(int k=0;k<N;k++)C[i][j]+=A[i][k]*B[k][j];
    printf("%f\n",C[N/2][N/2]);return 0;
}