C :

#include<stdio.h>
#include<string.h>
int main()
{
	char s[10],ch;
    int sum=0,ans=0;
	while(scanf("%s",s)!=EOF)
	{
		if(!strcmp(s,"negative"))      printf("-");
        else if(!strcmp(s,"zero"))     sum+=0;
        else if(!strcmp(s,"one"))      sum+=1;
        else if(!strcmp(s,"two"))      sum+=2;
        else if(!strcmp(s,"three"))    sum+=3;
        else if(!strcmp(s,"four"))     sum+=4;
        else if(!strcmp(s,"five"))     sum+=5;
        else if(!strcmp(s,"six"))      sum+=6;
        else if(!strcmp(s,"seven"))    sum+=7;
        else if(!strcmp(s,"eight"))    sum+=8;
        else if(!strcmp(s,"nine"))     sum+=9;
        else if(!strcmp(s,"ten"))      sum+=10;
        else if(!strcmp(s,"eleven"))   sum+=11;
        else if(!strcmp(s,"twelve"))   sum+=12;
        else if(!strcmp(s,"thirteen")) sum+=13;
        else if(!strcmp(s,"fourteen")) sum+=14;
        else if(!strcmp(s,"fifteen"))  sum+=15;
        else if(!strcmp(s,"sixteen"))  sum+=16;
        else if(!strcmp(s,"seventeen"))sum+=17;
        else if(!strcmp(s,"eighteen")) sum+=18;
        else if(!strcmp(s,"nineteen")) sum+=19;
        else if(!strcmp(s,"twenty"))   sum+=20;
        else if(!strcmp(s,"thirty"))   sum+=30;
        else if(!strcmp(s,"forty"))    sum+=40;
        else if(!strcmp(s,"fifty"))    sum+=50;
        else if(!strcmp(s,"sixty"))    sum+=60;
        else if(!strcmp(s,"seventy"))  sum+=70;
        else if(!strcmp(s,"eighty"))   sum+=80;
        else if(!strcmp(s,"ninety"))   sum+=90;
        else if(!strcmp(s,"hundred"))  sum*=100;
        else if(!strcmp(s,"thousand"))
		{
			ans+=sum*1000;
            sum=0;
		}
        else if(!strcmp(s,"million"))
		{
            ans+=sum*1000000;
            sum=0;
		}

        ch=getchar();

        if(ch=='\n')
		{
			printf("%d\n",ans+sum);
            sum=0;
            ans=0;
		}
	}
    return 0;
 }

C++ :

#include<iostream>
#include<cstdio>
#include<cstring>
#define maxn 100
char s[maxn];
int sum=0,ans=0;
int main()
{
    while(scanf("%s",s)!=EOF)
    {
        if(!strcmp(s,"negative"))printf("-");
        else if(!strcmp(s,"zero"))sum+=0;
        else if(!strcmp(s,"one"))sum+=1;
        else if(!strcmp(s,"two"))sum+=2;
        else if(!strcmp(s,"three"))sum+=3;
        else if(!strcmp(s,"four"))sum+=4;
        else if(!strcmp(s,"five"))sum+=5;
        else if(!strcmp(s,"six"))sum+=6;
        else if(!strcmp(s,"seven"))sum+=7;
        else if(!strcmp(s,"eight"))sum+=8;
        else if(!strcmp(s,"nine"))sum+=9;
        else if(!strcmp(s,"ten"))sum+=10;
        else if(!strcmp(s,"eleven"))sum+=11;
        else if(!strcmp(s,"twelve"))sum+=12;
        else if(!strcmp(s,"thirteen"))sum+=13;
        else if(!strcmp(s,"fourteen"))sum+=14;
        else if(!strcmp(s,"fifteen"))sum+=15;
        else if(!strcmp(s,"sixteen"))sum+=16;
        else if(!strcmp(s,"seventeen"))sum+=17;
        else if(!strcmp(s,"eighteen"))sum+=18;
        else if(!strcmp(s,"nineteen"))sum+=19;
        else if(!strcmp(s,"twenty"))sum+=20;
        else if(!strcmp(s,"thirty"))sum+=30;
        else if(!strcmp(s,"forty"))sum+=40;
        else if(!strcmp(s,"fifty"))sum+=50;
        else if(!strcmp(s,"sixty"))sum+=60;
        else if(!strcmp(s,"seventy"))sum+=70;
        else if(!strcmp(s,"eighty"))sum+=80;
        else if(!strcmp(s,"ninety"))sum+=90;
        else if(!strcmp(s,"hundred"))
        {
            sum*=100;
        }
        else if(!strcmp(s,"thousand"))
        {
            ans+=sum*1000;
            sum=0;
        }
        else if(!strcmp(s,"million"))
        {
            ans+=sum*1000000;
            sum=0;
        }
        char ch=getchar();
        if(ch=='\n')
        {
            printf("%d\n",ans+sum);
            sum=0;
            ans=0;
        }
    }
    return 0;
}