How can I finish this matrix multiplication code with an accumulator?

`MatrizA=3x4`

- `MatrizB=4x3`

- `Resultante=3x3`

:

```
for (j=o; j<n-1;j++){
for (i=0; i<m-1;i++){
Acumulador=0;
for (k=0; k<=P-1 ; k++){
acumulador= MatrizA[ i][k]* MatrizB[k][i]+ acumulador;
}
R-[i][j]=Acumulador;
}
}
```