Hi guys, sorry for the small things as portuguese.

printf("\nIniciar Programa!!\n\nIntroduza a largura e altura do tabuleiro.\n"); //sorry its portuguese, its asking the user to put the numbers of a rectangle 
scanf("%d %d", &Largura, &Altura); /
int Dimensao = Largura * Altura;

the problem is that if the user puts a char instead of a number the program stops working, i need to put showing a error when the user is "stupid xD", and dont know how to follow .