Compilare: user.c:1:19: warning: return type defaults to ‘int’ [enabled by default] long long p,k,i,n;main(){scanf("%lld",&p);for(n=2;p>k;n++)for(i=5,k=0;i<=n;i*=5)k+=n/i;printf("%lld",n-1);} ^ user.c: In function ‘main’: user.c:1:1: warning: implicit declaration of function ‘scanf’ [-Wimplicit-function-declaration] long long p,k,i,n;main(){scanf("%lld",&p);for(n=2;p>k;n++)for(i=5,k=0;i<=n;i*=5)k+=n/i;printf("%lld",n-1);} ^ user.c:1:26: warning: incompatible implicit declaration of built-in function ‘scanf’ [enabled by default] long long p,k,i,n;main(){scanf("%lld",&p);for(n=2;p>k;n++)for(i=5,k=0;i<=n;i*=5)k+=n/i;printf("%lld",n-1);} ^ user.c:1:1: warning: implicit declaration of function ‘printf’ [-Wimplicit-function-declaration] long long p,k,i,n;main(){scanf("%lld",&p);for(n=2;p>k;n++)for(i=5,k=0;i<=n;i*=5)k+=n/i;printf("%lld",n-1);} ^ user.c:1:88: warning: incompatible implicit declaration of built-in function ‘printf’ [enabled by default] long long p,k,i,n;main(){scanf("%lld",&p);for(n=2;p>k;n++)for(i=5,k=0;i<=n;i*=5)k+=n/i;printf("%lld",n-1);} ^