Najdi go Zbirot - SP Lab3

#include <stdio.h>
int main(){
    int sum=0,prev=0;
    char c;
    while(scanf("%c",&c)&&c!='!'){
        if(c=='0'||c=='1'||c=='2'||c=='3'||c=='4'||c=='5'||c=='6'||c=='7'||c=='8'||c=='9'){
            prev*=10+c-'0';
        }
        else{
        sum+=prev;
            prev=0;
        }
    }
    sum+=prev;
    printf("%d", sum);
}